Elastic compression stockings one year after DVT diagnosis: Who might discontinue?

BACKGROUND: Elastic compression stockings (ECS) are uncomfortable to wear but may prevent post-thrombotic syndrome (PTS). The ability to predict PTS may help clinical decision making regarding the optimal duration of ECS after deep vein thrombosis (DVT). AIMS: Predefined endpoint analysis of the Octavia study that randomized patients who compliantly used ECS up to one year after DVT to continue or discontinue ECS treatment. Primary aim was to identify predictors of PTS. METHODS: Patient characteristics were collected and ultrasonography was performed to assess reflux, residual thrombosis and persistent thrombus load 12 months after DVT. Multivariable analyses were performed to identify factors related to PTS. RESULTS: Thrombus score ≥ 3, BMI ≥ 26, duration of symptoms before DVT diagnosis ≥ 8 days and a Villalta score of 2-4 points were statistically significant predictors of PTS. The predictive value for PTS for the assessed variables was not different between the 2 treatment groups. In the stop ECS group, 3.2% (95%CI 0.08-18) of patients without any predictors for PTS were diagnosed with mild PTS during follow-up, and none with severe PTS, for a sensitivity of 98% (95% CI 89-100), a specificity of 14% (95% CI 10-20), a positive predictive value of 20% (95% CI 19-22), and a negative predictive value of 97% (95% CI 81-100). CONCLUSION: We identified 4 predictors of PTS occurring in the 2nd year after DVT. Our findings may be used to decide on whether to continue ECS treatment for an additional year, after one year of compliant ECS use, keeping in mind that patients with none of the predictors will have the lowest PTS incidence.

T cells are the critical source of IL-4/IL-13 in a mouse model of allergic asthma.

BACKGROUND: IL-4 and IL-13 play a crucial role during allergic asthma. Both cytokines can be produced by T cells and a variety of cell types of the innate immune system. The relative contribution of T-cell-derived vs innate IL-4/IL-13 for allergic inflammation and airway hyperreactivity remains unclear. METHODS: We compared the severity of OVA/alum-induced allergic lung inflammation in WT BALB/c mice to mice that lack expression of IL-4/IL-13 only in T cells (4-13Tko) or in all cell types (4-13ko). RESULTS: T-cell-derived IL-4/IL-13 was required for IgG1 and IgE production, recruitment of eosinophils and basophils to the lung, goblet cell hyperplasia, expression of Muc5ac, Clca3, and RELMß, differentiation of alternatively activated macrophages, and airway hyperreactivity. Interestingly, ILC2 recruitment to the lung occurred independently of T-cell-derived IL-4/IL-13 but was diminished in the absence of IL-4/IL-13 from all cell types. Thus, the number of IL-4/IL-13-competent ILC2s did not correlate with the severity of lung pathology. CONCLUSIONS: Th2 cells appear to be the critical IL-4/IL-13-expressing cell type for the induction of allergic airway inflammation and airway hyperreactivity. The translational perspective of our results indicates that inhibition or reprogramming of Th2 cells may be very effective for the treatment of allergic asthma.

Commuter migration: work environment factors influencing nurses' decisions regarding choice of employment.

Nurse migration is of global concern for every country, and study of migration can provide critical information for managers concerned with nurse recruitment and retention. This mixed-methods research examined factors influencing registered nurses' (RNs') decisions to work in their home country, Canada, or to commute daily to a nursing position in the United States. Measures included nurses' feelings about their work environment conditions, work status congruence (the goodness of fit between employer expectations and their own regarding hours and times worked), professional development opportunities, and their perceptions of organizational support and autonomy (freedom and independence) in the workplace. All work environment variables were significantly higher for nurses working in Michigan. Qualitative results supported these survey findings, providing additional information about nurses' satisfaction. Nurses in our sample were more satisfied with all the work environment factors examined, even when stress from commuting out of country was experienced. The environmental issues examined in this study should be considered by nurse managers concerned with recruitment and retention of nurses.

PEST-domain-enriched tyrosine phosphatase and glucocorticoids as regulators of anaphylaxis in mice.

BACKGROUND: PEST-domain-enriched tyrosine phosphatase (PEP) is a protein tyrosine phosphatase exclusively expressed in hematopoietic cells. It is a potent negative regulator of T-cell receptor signalling that acts on receptor-coupled protein tyrosine kinases. PEST-domain-enriched tyrosine phosphatase is also expressed in mast cell and is positively regulated by glucocorticoids, but its function is unknown. In this communication, the function of PEP is analysed in mast cells. METHODS: Signal transduction cascades following IgE receptor cross-linking were compared in bone marrow-derived mast cells (BMMC) from PEP(-/-) and PEP(+/+) mice. Furthermore, antigen-induced passive systemic anaphylaxis (PSA) was analysed in PEP(+/+) and PEP(-/-) mice. RESULTS: Bone marrow-derived mast cells from PEP(-/-) mice showed impaired PLCγ1 phosphorylation and Ca(2+) mobilization. Additionally, mice deficient in PEP showed impaired mast cell degranulation and were less susceptible to PSA. Treatment of wild-type BMMC or mice with an Au(I)-phosphine complex that selectively inhibits PEP activity produced defects in Ca(2+) signalling pathway and reduced anaphylaxis similar to that caused by the deletion of the PEP gene. Glucocorticoid that negatively regulates a wide range of mast cell action increased PEP expression and only partially inhibited anaphylaxis. However, glucocorticoid potently inhibited anaphylaxis when combined with the PEP inhibitor. CONCLUSIONS: PEST-domain-enriched tyrosine phosphatase is an important positive regulator of anaphylaxis. Pharmacological inhibition of its activity together with glucocorticoid administration provide an effective rescue for PSA in mice.

Kalanchoe pinnata inhibits mast cell activation and prevents allergic airway disease.

Aqueous extract of Kalanchoe pinnata (Kp) have been found effective in models to reduce acute anaphylactic reactions. In the present study, we investigate the effect of Kp and the flavonoid quercetin (QE) and quercitrin (QI) on mast cell activation in vitro and in a model of allergic airway disease in vivo. Treatment with Kp and QE in vitro inhibited degranulation and cytokine production of bone marrow-derived mast cells following IgE/FcɛRI crosslinking, whereas treatment with QI had no effect. Similarly, in vivo treatment with Kp and QE decreased development of airway hyperresponsiveness, airway inflammation, goblet cell metaplasia and production of IL-5, IL-13 and TNF. In contrast, treatment with QI had no effect on these parameters. These findings demonstrate that treatment with Kp or QE is effective in treatment of allergic airway disease, providing new insights to the immunomodulatory functions of this plant.

Mast cells and mast cell-derived factors in the regulation of allergic sensitization.

Mast cells have been mainly regarded as effector cells in IgE-dependent mucosal immunity, including the host response to helminthic parasites but also the formidable and sometimes fatal anaphylactic reactions to inhaled or ingested allergens. Work performed mostly within the last decade revealed novel functions for mast cells as critical initiators of fast inflammatory reactions upon IgE-independent activation. Thus, their role as a sentinel in innate immunity also suggests that mast cells are able to bridge innate and adaptive immunity. Herein, we will summarize the accumulating evidence that mast cells are also able to promote and to modulate the development of adaptive immune reactions with emphasis on their role in allergic sensitization in skin and lung. Based on murine data published so far, it is becoming apparent that mast cells and their mediators are of critical relevance for allergen sensitization under conditions which more closely resemble physiological contact with allergens. Yet, the function of mast cells can sometimes be bypassed using vigorous sensitization protocols, a finding which should be taken into account when animal models for complex human diseases are investigated.

Mast cell-derived tumour necrosis factor is essential for allergic airway disease.

Mast cells are thought to contribute to allergic airway disease. However, the role of mast cell-produced mediators, such as tumour necrosis factor (TNF), for the development of allergic airway disease is unclear. In order to define the role of mast cells in acute allergic airway disease two strains of mast cell-deficient mice (Kit(W/Wv) and Kit(W-sh/W-sh)) were studied. Compared with their wild-type littermates, Kit(W/Wv) and Kit(W-sh/W-sh) mice developed significantly lower airway responsiveness to methacholine and less airway inflammation and goblet cell metaplasia, following sensitisation in the absence of adjuvant and airway challenge. Transfer of bone marrow-derived mast cells (BMMCs) from wild-type mice to Kit(W-sh/W-sh) mice reconstituted both airway responsiveness and inflammation to levels similar to those in sensitised and challenged wild-type mice. In contrast, sensitised Kit(W-sh/W-sh) mice reconstituted with BMMCs from TNF-deficient mice were still severely impaired in their ability to develop airway hyperresponsiveness, inflammation or goblet cell metaplasia following allergen challenge. The present results demonstrate the significance of mast cells in the development of airway disease and highlight the importance of mast cell-derived tumour necrosis factor in these responses.

Decreased number of acetylcholine receptors is the mechanism that alters the time course of muscle relaxants in myasthenia gravis: a study in a rat model.

BACKGROUND: In myasthenic patients, the time course of action of non-depolarizing neuromuscular blocking agents is prolonged and the sensitivity is increased. We used our antegrade perfused rat peroneal nerve anterior tibialis muscle model to investigate if this altered time course of effect and sensitivity can be explained by the decreased acetylcholine receptor concentration that is caused by the disease. METHODS: Functional acetylcholine receptors were reduced by administration of alpha-bungarotoxin or by injecting monoclonal antibodies against rat acetylcholine receptors (experimental autoimmune myasthenia gravis). After induction of anaesthesia, the model was set up and perfusion of the tibialis anterior muscle with blood was started. After stabilization of the twitch, rocuronium or pancuronium were infused until 90% block was obtained. Twitch data and infusion data were recorded and used to calculate the time course of effect and potency. RESULTS: The potency of neuromuscular blocking agents was increased and the offset of the neuromuscular block was prolonged in both the alpha-bungarotoxin groups and the experimental autoimmune myasthenia gravis groups compared to controls. CONCLUSION: This study shows that the increased sensitivity to neuromuscular-blocking agents in myasthenia gravis can be accounted for by a decreased number of acetylcholine receptors. It also shows that the antegrade perfused rat peroneal nerve anterior tibialis muscle model is a suitable model to study the effects of myasthenia gravis on the time course of effect of neuromuscular blocking agents.

[Diabetic gastroparesis]. / La gastroparésie diabétique.

Diabetic gastroparesis corresponds to symptomatic as well as asymptomatic gastric retention without organic abnormality of stomach, pylorus or gut. This complication associated with autonomic neuropathy is found in about 50% of patients with type 1 and type 2 diabetes. It may be clinically important when it is associated with gastrointestinal symptoms limiting quality of life, alterations in glycaemic control and changes in oral drug absorption. In addition, acute changes in blood glucose concentration affect gastric motor function: gastric emptying is slowed down during hyperglycaemia and accelerated during hypoglycaemia. The diagnosis of gastroparesis may be confirmed by scintigraphy assessment of gastric emptying, preferably using a solid meal. Unfortunately, treatment options remain limited and often unsatisfactory. They first rely on life-style and dietary modifications. If necessary, pharmacological agents (metoclopramide, domperidone, cisapride, and erythromycin) may be considered. Cisapride is actually the most powerful agent for chronic use, but the risk of cardiac toxicity (increase of QT with "torsade de pointe") limits its general use. In some diabetic patients, gastroparesis may contribute to erratic glucose excursions, with precocious postprandial hypoglycaemia, late hyperglycaemia, and/or delayed recovery from hypoglycaemia after carbohydrate ingestion. Sometimes, the initiation of intensive insulin therapy and the use of prokinetic drugs could lead to significant improvement of blood glucose control in patients with diabetic gastroparesis.

Immunoregulation in experimental autoimmune myasthenia gravis--about T cells, antibodies, and endplates.

Experimental autoimmune myasthenia gravis (EAMG) can be induced in a large number of animal species by active immunization (AI) AChR, by passive transfer (PT) of anti-AChR antibodies, by autologous bone marrow transplantation and cyclosporin (BMT-Cy), or spontaneously. Depending on the model used, different immunological mechanisms are operational. In the AI model, the T cell is pivotal in directing the anti-AChR antibody production towards pathogenic, that is, cross-linking and complement-fixing antibodies. Injection of anti-AChR antibodies alone suffices to induce EAMG, excluding the role of specific cell-mediated immune responses in the effector phase of the disease. Aged animals are resistant to the induction of AI and PT EAMG. This resistance is localized at the postsynaptic membrane containing more AChR-anchoring proteins, including S-laminin and rapsyn in aged animals. In BMT-CyA EAMG, a dysregulation of the immune system in the absence of immunization is capable of inducing myasthenia. The role of these animal models in relation to pathogenesis and immunotherapy is discussed.

The role of antibodies in myasthenia gravis.

Myasthenia gravis is an autoimmune disease associated with antibodies directed to the postsynaptic acetylcholine receptor. These antibodies reduce the number of receptors. Autoantibodies against AChR and other muscle antigens can be used for the diagnosis of myasthenia gravis and related disorders. The origin and the role of these antibodies in the disease are discussed. Experimental autoimmune myasthenia gravis, an experimental model closely mimicking the disease, has provided answers to many questions about the role of antibodies, complement macrophages and AChR anchor proteins. Genetically modified anti-AChR antibodies may also be used in the future to treat myasthenia.

Glucocorticoids inhibit MAP kinase via increased expression and decreased degradation of MKP-1.

Glucocorticoids inhibit the proinflammatory activities of transcription factors such as AP-1 and NF-kappa B as well as that of diverse cellular signaling molecules. One of these signaling molecules is the extracellular signal-regulated kinase (Erk-1/2) that controls the release of allergic mediators and the induction of proinflammatory cytokine gene expression in mast cells. The mechanism of inhibition of Erk-1/2 activity by glucocorticoids is unknown. Here we report a novel dual action of glucocorticoids for this inhibition. Glucocorticoids increase the expression of the MAP kinase phosphatase-1 (MKP-1) gene at the promoter level, and attenuate proteasomal degradation of MKP-1, which we report to be triggered by activation of mast cells. Both induction of MKP-1 expression and inhibition of its degradation are necessary for glucocorticoid-mediated inhibition of Erk-1/2 activation. In NIH-3T3 fibroblasts, although glucocorticoids up-regulate the MKP-1 level, they do not attenuate the proteasomal degradation of this protein and consequently they are unable to inhibit Erk-1/2 activity. These results identify MKP-1 as essential for glucocorticoid-mediated control of Erk-1/2 activation and unravel a novel regulatory mechanism for this anti-inflammatory drug.

Reactions of older employees to organizational downsizing: the role of gender, job level, and time.

This panel study examined the reactions of 187 federal government employees aged 45 and older during the initial phase of a large-scale downsizing and 20 months later. There were few significant differences in the reactions of older men and women. Respondents in management positions reported significantly more positive attitudes toward their job and the organization than did respondents in nonmanagement jobs. Compared with the initial phase of the downsizing, respondents reported a significant decrease in commitment to the organization 20 months later. For the two dimensions of job insecurity, perceived threat of job loss decreased, whereas sense of powerlessness over decisions affecting the future of one's job increased. A major area of concern for management is the low level of organizational trust and morale reported by the respondents at both time periods.

Identification and functional characterization of human CD4(+)CD25(+) T cells with regulatory properties isolated from peripheral blood.

A subpopulation of peripheral human CD4(+)CD25(+) T cells that expresses CD45RO, histocompatibility leukocyte antigen DR, and intracellular cytotoxic T lymphocyte-associated antigen (CTLA) 4 does not expand after stimulation and markedly suppresses the expansion of conventional T cells in a contact-dependent manner. After activation, CD4(+)CD25(+) T cells express CTLA-4 on the surface detectable for several weeks. These cells show a G1/G0 cell cycle arrest and no production of interleukin (IL)-2, IL-4, or interferon (IFN)-gamma on either protein or mRNA levels. The anergic state of CD4(+)CD25(+) T cells is not reversible by the addition of anti-CD28, anti-CTLA-4, anti-transforming growth factor beta, or anti-IL-10 antibody. However, the refractory state of CD4(+)CD25(+) T cells was partially reversible by the addition of IL-2 or IL-4. These data demonstrate that human blood contains a resident T cell population with potent regulatory properties.

IL-9 and IL-13 production by activated mast cells is strongly enhanced in the presence of lipopolysaccharide: NF-kappa B is decisively involved in the expression of IL-9.

Mast cells, due to their ability to produce a large panel of mediators and cytokines, participate in a variety of processes in adaptive and innate immunity. Herein we report that in primary murine bone marrow-derived mast cells activated with ionomycin or IgE-Ag the bacterial endotoxin LPS strongly enhances the expression of IL-9 and IL-13, but not IL-4. This costimulatory effect of LPS is absent in activated mast cells derived from the LPS-hyporesponsive mouse strain BALB/c-LPS(d), although in these cells the proinflammatory cytokine IL-1 can still substitute for LPS. The enhanced production of mast cell-derived IL-13 in the presence of IL-1 is a novel observation. Coactivation of mast cells with LPS leads to a synergistic activation of NF-kappa B, which is shown by an NF-kappa B-driven reporter gene construct. In the presence of an inhibitor of NF-kappa B activation, the production of IL-9 is strongly decreased, whereas the expression of IL-13 is hardly reduced, and that of IL-4 is not affected at all. NF-kappa B drives the expression of IL-9 via three NF-kappa B binding sites within the IL-9 promoter, which we characterize using gel shift analyses and reporter gene assays. In the light of recent reports that strongly support critical roles for IL-9 and IL-13 in allergic lung inflammation, our results emphasize the potential clinical importance of LPS as an enhancer of mast cell-derived IL-9 and IL-13 production in the course of inflammatory reactions and allergic diseases.

Downsizing-initiated job transfer of hospital nurses: how do the job transferees fare?

In this longitudinal panel study, the authors compared the reactions to hospital amalgamation of 66 nurses who had been transferred to a different unit for a downsizing-related reason (bumped/displaced, unit closed, redundancy) with the reactions of 181 nurses who remained on their same unit. Prior to any job transfers, the two groups perceived comparable levels of support and held similar attitudes towards their job and the hospital. Two years later, after job transfers had taken place, transferred nurses perceived significantly lower coworker support. They also reported a significantly greater decrease in organizational commitment than nurses who were not transferred. However, both groups reported a significant decrease between time a and time 2 in perceived organizational support, satisfaction with amount of work and career future, hospital identification, and organization trust. Overall, the results indicate that the downsizing associated with the amalgamation of the hospitals had a highly negative effects not only on those nurses who were transferred because of the downsizing but also on those nurses who remained on their original unit.

Murine bone marrow-derived mast cells as potent producers of IL-9: costimulatory function of IL-10 and kit ligand in the presence of IL-1.

Recently, the Th2-type cytokine IL-9 was identified by genetic mapping analyses as a key mediator that determines the susceptibility to asthma. This has been further supported by data from IL-9-transgenic mice in which the overexpression of IL-9 in the lung causes airway inflammation, mast cell hyperplasia, and bronchial hyperresponsiveness. In an accompanying paper, we demonstrate that murine bone marrow-derived mast cells (BMMC) after stimulation with either ionomycin, a combination of ionomycin and IL-1, or via IgE-Ag complexes and IL-1 are very potent producers of IL-9. Herein we show that a dramatic increase of IL-9 production is observed when BMMC activated with ionomycin/IL-1 or with IgE-Ag complexes/IL-1 are treated with either additional kit ligand (KL) or IL-10. Both KL and IL-10 considerably enhance the production of IL-9 mRNA and protein. We were also able to demonstrate that the production of endogenous IL-10 by activated mast cells acts on the production of IL-9. Half-life measurements of IL-9 mRNA revealed no significant effect by KL, but a 2-fold increase of mRNA stability under the influence of IL-10. Reporter gene assays of transfected BMMC showed an enhanced transcriptional activity of the IL-9 promoter in the presence of either IL-10 or KL compared with cells stimulated only with a combination of IL-1 and ionomycin. The influence of KL and IL-10 might be of physiological importance, because it is known that both cytokines are produced by bronchial epithelial cells.

In activated mast cells, IL-1 up-regulates the production of several Th2-related cytokines including IL-9.

Mast cells can play detrimental roles in the pathophysiology and mortality observed in anaphylaxis and other Th2-dominated allergic diseases. In contrast, these cells contribute to protective host defense mechanisms against parasitic worm infections. After IgE/Ag activation, mast cells can produce multiple cytokines that may enhance allergic inflammations, while a similar panel of Th2-related cytokines may support immunological strategies against parasites. Here we report that in primary mouse bone marrow-derived mast cells activated by ionomycin or IgE/Ag, the proinflammatory mediator IL-1 (alpha or beta) up-regulated production of IL-3, IL-5, IL-6, and IL-9 as well as TNF, i.e., cytokines implicated in many inflammatory processes including those associated with allergies and helminthic infections. IL-1 did not induce significant cytokine release in the absence of ionomycin or IgE/Ag, suggesting that Ca-dependent signaling was required. IL-1-mediated enhancement of cytokine expression was confirmed at the mRNA level by Northern blot and/or RT-PCR analysis. Our study reveals a role for IL-1 in the up-regulation of multiple mast cell-derived cytokines. Moreover, we identify mast cells as a novel source of IL-9. These results are of particular importance in the light of recent reports that strongly support a central role of IL-9 in allergic lung inflammation and in host defense against worm infections.

The importance of the light chain for the epitope specificity of human anti-U1 small nuclear RNA autoantibodies present in systemic lupus erythematosus patients.

Abs to U1 RNA are frequently found in patients suffering from systemic lupus erythematosus overlap syndromes and Ab titers correlate with disease activity. We describe the isolation of the first human anti-U1 RNA autoantibodies from a combinatorial IgG library made from the bone marrow of a systemic lupus erythematosus patient. With the use of phage display technology, two anti-U1 RNA single-chain variable fragment (scFv) Abs were selected. Both high affinity anti-U1 RNA Ab fragments (Kd approximately 1 nM) recognize stem II of U1 RNA and were derived from the same heavy chain gene (VH3-11) and the same lambda (3r) light chain gene although somatic mutations, predominantly present in the complementarity-determining regions, are different. Experiments, in which the heavy chain genes of both anti-U1 RNA scFvs were reshuffled with the original light chain repertoire of the patient resulted, after selection on stem loop II, in a large number of RNA-binding Ab fragments. All these stem loop II-specific RNA binding clones used a similar, but not identical, 3r lambda light chain. When scFvs were selected from the reshuffled libraries by stem loop IV, representing the other autoantigenic site of U1 RNA, most selected Ab clones did react with stem loop IV, but no longer with stem loop II. The stem loop IV-reactive Ab clones contained different, not 3r-related, light chains. These results point to a major role for the light chain in determining the sequence specificity of these disease-related anti-U1 RNA Abs. The possibility that secondary light chain rearrangements are involved in this autoimmune response is discussed.