Effects of established allergen sensitization on immune and airway responses after secondary allergen sensitization

BACKGROUND: Spreading of sensitization with clinical manifestation of allergy is often observed in atopic individuals. OBJECTIVE: To investigate the effects of an established primary allergen sensitization on immune responses and airway inflammation/reactivity on secondary allergen sensitization and airway challenges in a murine model. METHODS: Balb/c mice were primarily sensitized intraperitoneally with ovalbumin or PBS, followed by systemic sensitization and airway challenges with latex extract as a secondary, unrelated allergen. Purely sham-sensitized animals were included as controls. In a second set of experiments, the primary and secondary allergens were switched. RESULTS: Sensitization with ovalbumin before sensitization with latex resulted in increased production of total and latex-specific (Hev b 3-specific) IgE and IgG(1), and enhanced secretion of T(H)2-cytokines by spleen mononuclear cells cultured with mitogen compared with single latex-sensitized mice. Furthermore, airway challenges of double-sensitized mice (ovalbumin + latex) with latex caused a significant increase in airway reactivity compared with purely latex-sensitized and challenged animals. These effects were dependent on dosing and timing of the primary sensitization in relation to the secondary sensitization and independent of the primary allergen used. CONCLUSION: Primary sensitization boosted systemic T(H)2 immune responses and enhanced the development of airway reactivity after sensitization and airway challenges with a secondary, unrelated allergen. This effect of consecutive priming was dependent on the strength of the primary sensitization but independent of the allergen used. The results explain the increased susceptibility toward sensitization spreading in atopic individuals. CLINICAL IMPLICATIONS: Because sensitization spreading is facilitated by primary sensitization, early prevention measurements or immunotherapy should be considered at this stage of monosensitization.     

Unemployment and ill health: a connection through inflammation?

Background  

Unemployment is a source of acute and long-term psychosocial stress. Acute and chronic psychosocial stress can induce pronounced changes in human immune responses. In this study we tested our hypothesis that stress-induced low-grade tissue inflammation is more prevalent among the unemployed.     

Are factors associated with suicidal ideation true risk factors?

Background  Adverse life events or the commencement of adverse lifestyles associate with suicidal ideation, but most associations only have been identified in cross-sectional studies. More information is needed about whether they are true risk factors and independently predict the development of suicidal ideation. Method  A sample of the general population from Eastern Finland (n = 1,339) was followed-up for three-years with baseline and two follow-up assessments using postal questionnaires. The main adverse life events and changes in lifestyles were screened at baseline and on one- and three-year follow-up. The Beck Depression Inventory was used to assess the level of depression and the presence of suicidal ideation. Results  Suicidal ideation was common in the sample (annual incidence 4.3%). At baseline it associated with a cluster of adverse life events and lifestyles, as well as depression. Nevertheless, only the Beck Depression Inventory score on 3-year follow-up (OR 1.33, 95% CI 1.22–1.45) and the onset of daily smoking during the follow-up period (OR 5.38, 95% CI 1.41–20.62) independently predicted the presence of suicidal ideation on 3-year follow-up among those who had been non-suicidal at baseline and on 1-year follow-up. Conclusion  Depressive mood appears to be a necessary precondition for the occurrence of suicidal ideation even after adverse life events.     

Molecular interaction of droperidol with human ether-a-go-go-related gene channels: prolongation of action potential duration without inducing early afterdepolarization

BACKGROUND: The cardiac safety of droperidol given at antiemetic doses is a matter of debate. Although droperidol potently inhibits human ether-a-go-go-related gene (HERG) channels, the molecular mode of this interaction is unknown. The role of amino acid residues typically mediating high-affinity block of HERG channels is unclear. It is furthermore unresolved whether droperidol at antiemetic concentrations induces action potential prolongation and arrhythmogenic early afterdepolarizations in cardiac myocytes. METHODS: Molecular mechanisms of HERG current inhibition by droperidol were established using two-electrode voltage clamp recordings of Xenopus laevis oocytes expressing wild-type and mutant channels. The mutants T623A, S624A, V625A, Y652A, and F656A were generated by site-directed mutagenesis. The effect of droperidol on action potentials was investigated in cardiac myocytes isolated from guinea pig hearts using the patch clamp technique. RESULTS: Droperidol inhibited currents through HERG wild-type channels with a concentration of half-maximal inhibition of 0.6-0.9 microM. Droperidol shifted the channel activation and the steady state inactivation toward negative potentials while channel deactivation was not affected. Current inhibition increased with membrane potential and with increasing duration of current activation. Inhibition of HERG channels was similarly reduced by all mutations. Droperidol at concentrations between 5 and 100 nM prolonged whereas concentrations greater than 300 nm shortened action potentials. Early afterdepolarizations were not observed. CONCLUSIONS: Droperidol is a high-affinity blocker of HERG channels. Amino acid residues typically involved in high-affinity block mediate droperidol effects. Patch clamp results and computational modeling allow the hypothesis that interaction with calcium currents may explain why droperidol at antiemetic concentrations prolongs the action potential without inducing early afterdepolarizations.     

Acute changes in pulmonary artery pressures due to exercise and exposure to high altitude do not cause left ventricular diastolic dysfunction

BACKGROUND: Altitude-induced pulmonary hypertension has been suggested to cause left ventricular (LV) diastolic dysfunction due to ventricular interaction. In this study, we evaluate the effects of exercise- and altitude-induced increase in pulmonary artery pressures on LV diastolic function in an interventional setting investigating high-altitude pulmonary edema (HAPE) prophylaxis. METHODS: Among 39 subjects, 29 were HAPE susceptible (HAPE-S) and 10 served as control subjects. HAPE-S subjects were randomly assigned to prophylactic tadalafil (10 mg), dexamethasone (8 mg), or placebo bid, starting 1 day before ascent. Doppler echocardiography at rest and during submaximal exercise was performed at low altitude (490 m) and high altitude (4,559 m). The ratio of early transmitral inflow peak velocity (E) to atrial transmitral inflow peak velocity (A), pulmonary venous flow parameters, and tissue velocity within the septal mitral annulus during early diastole (E') were used to assess LV diastolic properties. LV filling pressures were estimated by E/E'. Systolic right ventricular to atrial pressure gradients (RVPGs) were measured in order to estimate pulmonary artery pressures. RESULTS: At 490 m, E/A decreased similarly with exercise in HAPE-S and control subjects (HAPE-S, 1.5 +/- 0.3 to 1.3 +/- 0.3; control, 1.7 +/- 0.4 to 1.3 +/- 0.3; p = 0.12 between groups) [mean +/- SD], whereas RVPG increased significantly more in HAPE-S subjects (20 +/- 5 to 43 +/- 9 mm Hg vs 18 +/- 3 to 28 +/- 3 mm Hg, p < 0.001). Changes in RVPG levels during exercise did not correlate with changes in E/A (p > 0.1). From 490 to 4,559 m, no correlations between changes in RVPG and changes in E/A or atrial reversal (both p > 0.1) were observed. Neither of the groups showed an increase in E/E' from 490 to 4,559 m. CONCLUSION: Increased pulmonary artery pressure associated with exercise and acute exposure to 4,559 m appears not to cause LV diastolic dysfunction in healthy subjects. Therefore, ventricular interaction seems not to be of hemodynamic relevance in this setting.     

Delayed tumor onset and reduced tumor growth progression after immunization with a Her-2/neu multi-peptide vaccine and IL-12 in c-<Emphasis Type="Italic">neu</Emphasis> transgenic mice

Passive immunotherapy with monoclonal antibodies is a routinely performed but cost intensive treatment against certain cancers. Induction of humoral anti-tumor responses by active peptide immunization has therefore become a favorable treatment concept. We have recently identified three peptides representing B-cell epitopes of the extracellular domain of Her-2/neu each of them inducing Her-2/neu specific immune responses with anti-tumor activity in vitro. The present study was performed to evaluate the in vivo protective capacity of a combined vaccination with these three peptides in FVB/N transgenic mice spontaneously developing c-neu overexpressing breast cancers. The three Her-2/neu peptides coupled to tetanus toxoid were administered with or without addition of recombinant IL-12. At the time all untreated mice had developed tumors about 40% of peptide-immunized mice and nearly 60% of mice immunized with the peptide vaccine co-applied with IL-12 remained tumor free. Moreover, co-administration of IL-12 had a significant impact on the retardation of tumor progression. The enhanced anti-tumor efficacy of the vaccine by IL-12 was associated with a Th1 biased immune response as demonstrated by an increased IFN-γ production in vitro and elevated Her-2-specific IgG levels. Our findings clearly demonstrate that this multi-peptide vaccine is effective in tumor prevention and support its use against minimal disease, drug-resistant tumors or even for prophylaxis against cancers overexpressing Her-2/neu. Stefan Wagner and Joanna Jasinska contributed equally to this work.     

Serological markers for monitoring disease progression in noncirrhotic primary biliary cirrhosis on ursodeoxycholic acid therapy

Background/Aim: Liver biopsy has so far been the only method to accurately follow the progression of primary biliary cirrhosis (PBC). The stage and the severity of lymphocytic piecemeal necrosis (LPN) have been shown to be an independent factor for the development of cirrhosis. In this 3‐year prospective study, we evaluated the diagnostic value of several liver function tests, surrogate markers of fibrogenesis, hyaluronic acid (HA), procollagen III N‐terminal peptide (S‐PIIINP), cholestanol and plant sterols in noncirrhotic PBC patients treated with ursodeoxycholic acid (UDCA) or with UDCA and budesonide to assess the stage, inflammation and fibrosis. Methods: Seventy‐seven stage I–III PBC patients were included into the study, with control biopsy at 36 months. Serum liver enzymes, bile acids (BA), HA, PIIINP, immunoglobulins, lipids and cholesterol precursors and plant sterols were measured at baseline and at 36 months. Results: Aspartate aminotransferase (AST), HA, BA and PIINP were significantly different between stages I to III and differentiated mild (F0F1) from moderate (F2F3) fibrosis. The combination of these variables (PBC score) exhibited best sensitivity and specificity, compared with AST/platelet ratio, Forns' score and fibrosis index. Using a cut‐off value of 66 for the PBC score, the sensitivity was 81.4% and specificity was 65.2% for classifying the stage of PBC, regarding the stage the and fibrosis in noncirrhotic PBC. Conclusions: Serum HA, BA, PIIINP and AST may serve as valuable simple tools to monitor the treatment response to UDCA in early stages of PBC. Combinations of these biomarkers into a single index further potentiate the diagnostic value of such measurements.     

Partial remission indicates poor functioning and a high level of psychiatric symptoms: a 3-phase 6-year follow-up study on major depression

Patients with depression in partial remission are at high risk of relapse, but factors associated with being in this outcome group are not well known. We conducted a clinical survey to examine the course of major depression in 87 patients during a follow-up period of 6 years. Beck Depression Inventory (BDI) scores indicated the outcome of depression, i.e. remission, partial remission or fully symptomatic, at 6, 12 and 24 months and after 6 years. The prevalence of partial remission varied from 16% to 23% at different follow-ups. All symptom and functioning scale scores indicated at every assessment that the partial depression group managed better than those in the fully symptomatic group, but worse than those in remission. Partial remission was associated with a significant impairment in psychosocial functioning and a high level of symptoms throughout the follow-up. The partial remission group must be recognized and actively treated.