Eosinophilic inflammation and airway hyper-responsiveness are profoundly inhibited by a helminth (Ascaris suum) extract in a murine model of asthma

BACKGROUND

The increase of atopic disorders in developed countries has been associated with the decline of infectious diseases, including helminthic infections. We have already demonstrated that adult worm extracts from Ascaris suum (ASC) suppress the IgE antibody production against unrelated antigens.

OBJECTIVE

Here we investigated the influence of ASC on the development of pulmonary eosinophilic inflammation in a murine model of asthma.

METHODS

Heat-coagulated egg white alone (EWI) or mixed with ASC (EWI + ASC) was implanted subcutaneously in B10.A or C57BL/6 mice, and 14 days later they were challenged intratracheally with OVA or exposed to aerosolized OVA for 4 days.

RESULTS

The suppressive effect of ASC was demonstrated on the accumulation of cells into airways, with reduction of eosinophil numbers and of eosinophil peroxidase activity in EWI + ASC-immunized mice. This effect correlated with a marked reduction of IL-5 and IL-4 levels in the BAL from C57BL/6 and B10. A mice, respectively, and of eotaxin in BAL and lung tissue from both strains. OVA-specific IgG1 and IgE levels were also impaired in serum and BAL from these mice. Airway hyper-reactivity to methacholine was obtained in B10. A mice sensitized with EWI, but the respiratory mechanical parameters returned to normal levels in EWI + ASC-immunized mice.

CONCLUSION

These results indicate that ASC has a profound inhibitory effect on lung inflammation and hyper-responsiveness and that suppression of IL-5 or IL-4 and of eotaxin contributes to this effect.

A comparative analysis of three different techniques for the detection of breast cancer cells in bone marrow

Three different methods, morphologic, immunocytochemic, and fluorescence activated cell sorter (FC) analysis, were compared with respect to their efficiency in detecting breast cancer cells in bone marrow. In the first series of experiments, the three techniques were compared using bone marrow cells artificially mixed with a known amount of breast cancer cells, whereas in a second series bone marrow from breast cancer patients with bone metastases were used. The following results were obtained: When mixtures of the first series were analyzed, FC analysis detected from 1% to 10% of breast cancer cells in bone marrow (0.2% was a border line value), the morphologic method detected from 0.05% to 10%, and the immunocytochemic method, which was clearly superior, detected breast cancer cells in all mixtures (from 0.00025% to 10%). It was noted that, with both the morphologic and immunocytochemic methods, the percentage of breast cancer cells detected was 2 to 360 times higher than the percentage of added cells, and enrichment was inversely proportional to the percentage of added cells. This result could be a result of different separation of cells during centrifugation due to the different density of breast cancer cells. The superiority of the immunocytochemic method was confirmed in the second series of experiments.

Flavonone treatment reverses airway inflammation and remodelling in an asthma murine model

BACKGROUND AND PURPOSE

Asthma is an inflammatory disease that involves airway hyperresponsiveness and remodelling. Flavonoids have been associated to anti-inflammatory and antioxidant activities and may represent a potential therapeutic treatment of asthma. Our aim was to evaluate the effects of the sakuranetin treatment in several aspects of experimental asthma model in mice.

EXPERIMENTAL APPROACH

Male BALB/c mice received ovalbumin (i.p.) on days 0 and 14, and were challenged with aerolized ovalbumin 1% on days 24, 26 and 28. Ovalbumin-sensitized animals received vehicle (saline and dimethyl sulfoxide, DMSO), sakuranetin (20 mg kg(-1) per mice) or dexamethasone (5 mg kg(-1) per mice) daily beginning from 24th to 29th day. Control group received saline inhalation and nasal drop vehicle. On day 29, we determined the airway hyperresponsiveness, inflammation and remodelling as well as specific IgE antibody. RANTES, IL-5, IL-4, Eotaxin, IL-10, TNF-α, IFN-γ and GMC-SF content in lung homogenate was performed by Bioplex assay, and 8-isoprostane and NF-kB activations were visualized in inflammatory cells by immunohistochemistry.

KEY RESULTS

We have demonstrated that sakuranetin treatment attenuated airway hyperresponsiveness, inflammation and remodelling; and these effects could be attributed to Th2 pro-inflammatory cytokines and oxidative stress reduction as well as control of NF-kB activation.

CONCLUSIONS AND IMPLICATIONS

These results highlighted the importance of counteracting oxidative stress by flavonoids in this asthma model and suggest sakuranetin as a potential candidate for studies of treatment of asthma.

Aerobic training reverses airway inflammation and remodelling in an asthma murine model

Aerobic training (AT) decreases dyspnoea and exercise-induced bronchospasm, and improves aerobic capacity and quality of life; however, the mechanisms for such benefits remain poorly understood. The aim of the present study was to evaluate the AT effects in a chronic model of allergic lung inflammation in mice after the establishment of airway inflammation and remodelling. Mice were divided into the control group, AT group, ovalbumin (OVA) group or OVA+AT group and exposed to saline or OVA. AT was started on day 28 for 60 min five times per week for 4 weeks. Respiratory mechanics, specific immunoglobulin (Ig)E and IgG(1), collagen and elastic fibres deposition, smooth muscle thickness, epithelial mucus, and peribronchial density of eosinophils, CD3+ and CD4+, IL-4, IL-5, IL-13, interferon-gamma, IL-2, IL-1ra, IL-10, nuclear factor (NF)-kappaB and Foxp3 were evaluated. The OVA group showed an increase in IgE and IgG(1), eosinophils, CD3+, CD4+, IL-4, IL-5, IL-13, NF-kappaB, collagen and elastic, mucus synthesis, smooth muscle thickness and lung tissue resistance and elastance. The OVA+AT group demonstrated an increase of IgE and IgG(1), and reduction of eosinophils, CD3+, CD4+, IL-4, IL-5, IL-13, NF-kappaB, airway remodelling, mucus synthesis, smooth muscle thickness and tissue resistance and elastance compared with the OVA group (p<0.05). The OVA+AT group also showed an increase in IL-10 and IL-1ra (p<0.05), independently of Foxp3. AT reversed airway inflammation and remodelling and T-helper cell 2 response, and improved respiratory mechanics. These results seem to occur due to an increase in the expression of IL-10 and IL-1ra and a decrease of NF-kappaB.

Modulation of murine experimental asthma by Ascaris suum components

BACKGROUND

We have recently isolated two distinct components from Ascaris suum adult worms with different effects on the immune system: the allergenic protein of A. suum (APAS-3), which induces IgE antibody production, and suppressive protein of A. suum (PAS-1), which inhibits humoral and cellular immune responses induced by unrelated antigens. In this study, we investigated the immunomodulatory effect of PAS-1 on a murine model of asthma induced by APAS-3.

METHODS

BALB/c mice were immunized twice with APAS-3 or APAS-3 plus PAS-1 by the intraperitoneal and subcutaneous route (on days 0 and 7) and challenged twice with the same antigens intranasally (days 14 and 21). Two days after the last challenge, the allergic airway inflammation was evaluated by cellular migration, eosinophil peroxidase (EPO) activity, cytokine and chemokine production and pulmonary mechanical parameters.

RESULTS

The allergenic properties of APAS-3 were confirmed by the stimulation of anaphylactic IgE and IgG1 antibody production and eosinophilic airway inflammation and hyper-responsiveness. On the other hand, PAS-1-treated mice showed a marked suppression of cellular migration and EPO activity that correlated well with a significant reduction in the levels of IL-4, IL-5, eotaxin and RANTES in the bronchoalveolar lavage (BAL) fluid. In contrast, considerable amounts of IL-10 were observed in the BAL fluid of PAS-1-treated mice. Airway hyper-responsiveness was obtained in APAS-3-immunized mice, but the conductance of the respiratory system was restored to normal values in the presence of PAS-1.

CONCLUSION

These results indicate that A. suum allergenic protein APAS-3 induces a T helper 2-type immune response and, consequently, eosinophilic airway inflammation and hyper-responsiveness. Moreover, the modulatory protein PAS-1 has a marked suppressive effect on this response, and the inhibition of cytokine (IL-4, IL-5) and chemokine (eotaxin and RANTES) release, probably because of the presence of IL-10, may contribute to this effect.

PAS-1, a protein from Ascaris suum, modulates allergic inflammation via IL-10 and IFN-gamma, but not IL-12

Helminths and their products have a profound immunomodulatory effect upon the inductive and effector phases of inflammatory responses, including allergy. We have demonstrated that PAS-1, a protein isolated from Ascaris suum worms, has an inhibitory effect on lung allergic inflammation due to its ability to down-regulate eosinophilic inflammation, Th2 cytokine release and IgE antibody production. Here, we investigated the role of IL-12, IFN-gamma and IL-10 in the PAS-1-induced inhibitory mechanism using a murine model of asthma. Wild type C57BL/6, IL-12(-/-), IFN-gamma(-/-) and IL-10(-/-) mice were immunized with PAS-1 and/or OVA and challenged with the same antigens intranasally. The suppressive effect of PAS-1 was demonstrated on the cellular influx into airways, with reduction of eosinophil number and eosinophil peroxidase activity in OVA+PAS-1-immunized wild type mice. This effect well correlated with a significant reduction in the levels of IL-4, IL-5, IL-13 and eotaxin in BAL fluid. Levels of IgE and IgG1 antibodies were also impaired in serum from these mice. The inhibitory activity of PAS-1 was also observed in IL-12(-/-) mice, but not in IFN-gamma(-/-) and IL-10(-/-) animals. These data show that IFN-gamma and IL-10, but not IL-12, play an important role in the PAS-1 modulatory effect.

Early stages of Ascaris suum induce airway inflammation and hyperreactivity in a mouse model

The inflammatory and functional changes that occur in murine lung after infection with 2500 infective Ascaris suum eggs were studied in this work. A sequential influx of neutrophils, mononuclear cells and eosinophils occurred into airways concomitantly with migration of larvae from liver to the lungs. Histological analysis of the lung showed a severe intra-alveolar haemorrhage at the peak of larval migration (day 8) and the most intense inflammatory cell infiltrate on day 14. Ascaris L3 were found in alveolar spaces and inside bronchioles on day 8. The number of eosinophils was elevated in the blood on days 8 and 14. The peak of eosinophil influx into the lung was at day 14, as indicated by the high levels of eosinophil peroxidase activity, followed by their migration into the airways. The antibody response against egg and larval antigens consisted mainly of IgG1 and IgM, and also of IgE and anaphylactic IgG1, that cross-reacted with adult worm antigens. Total IgE levels were substantially elevated during the infection. Measurement of lung mechanical parameters showed airway hyperreactivity in infected mice. In conclusion, the murine model of A. suum infection mimics the Th2-induced parameters observed in pigs and humans and can be used to analyse the immunoregulatory properties of this helminth.

Long-term follow-up of a patient with Gitelman's syndrome

The long-term follow-up (from age 6 to 20 years) of a girl with Gitelman's syndrome, who had four hypomagnesaemic-tetanic episodes associated with normal plasma calcium, hypokalemia and hypocalciuria, is presented. During and after puberty, hypomagnesaemia was of the order of 0.41-0.49 mmol/l and plasma potassium was at the lower reference limit. The long-term clinical course and growth of this patient appeared good, but, magnesium supplementation reduces the risk of tetanic crises.

Gram-negative septicemia in patients with hematologic malignancies

The clinical records of 66 consecutive episodes of Gram-negative bacteremia occurring in 60 patients with hematologic malignancies during a 66-month period were reviewed to assess the major prognostic factors. The bacteremia-related mortality was 53%. Overall, Pseudomonas aeruginosa (54%) and Escherichia coli (24%) were the predominant isolates (fatality rate 78 and 31% respectively). The majority of patients (58/66) were granulocytopenic (PMN less than 1000/microliters). Among the 18 patients whose circulating granulocytes increased by one log10 or to above 1000/mmc during therapy, the fatality rate was 39%, as opposed to 70% in the 40 patients without such an increase. Pneumonia-associated bacteremia (56%) had a high fatality rate (73%) compared to isolated bacteremias (27%). Septic shock and inappropriate antibiotic therapy accounted for the highest mortality. Our data suggest that Pseudomonas etiology, persistent neutropenia, associated pneumonia, septic shock and inappropriate antibiotic therapy account for a bad prognosis in Gram-negative bacteremia in hematologic malignancies.

PAS-1, an Ascaris suum protein, modulates allergic airway inflammation via CD8+γδTCR+ and CD4+CD25+FoxP3+ T cells

We have previously demonstrated that PAS-1, a 200 kDa protein from Ascaris suum, has a potent immunomodulatory effect on humoral and cell-mediated responses induced by APAS-3 (an allergenic protein from A. suum) or unrelated antigens. In this study, we investigated the mechanisms by which PAS-1 is able to induce this effect on an allergic airway inflammation induced by OVA in mice. C57BL/6 mice were adoptively transferred on day 0 with seven different PAS-1-primed cell populations: PAS-1-primed CD19(+) or B220(+) or CD3(+) or CD4(+) or CD8(+) or CD4(+) CD25⁻ or CD4(+) CD25(+) lymphocytes. These mice were immunized twice with OVA and alum by intraperitoneal route (days 0 and 7) and challenged twice by intranasal route (days 14 and 21). Two days after the last challenge, the airway inflammation was evaluated by antibody levels, cellular migration, eosinophil peroxidase levels, cytokine and eotaxin production, and pulmonary mechanical parameters. Among the adoptively transferred primed lymphocytes, only CD4(+) CD25(+) , CD8(+) or the combination of both T cells impaired the production of total IgE and OVA-specific IgE and IgG1 antibodies, eosinophilic airway inflammation, Th2-type cytokines (IL-4, IL-5 and IL-13), eotaxin release and airway hyperreactivity. Moreover, airway recruited cells from CD4(+) CD25(+) and CD8(+) T-cell recipient secreted more IL-10/TGF-β and IFN-γ, respectively. Moreover, we found that PAS-1 expands significantly the number of CD4(+) CD25(+) FoxP3(+) and CD8(+) γδTCR(+) cells. In conclusion, these findings demonstrate that the immunomodulatory effect of PAS-1 is mediated by these T-cell subsets.

Immunoglobulin E is not required for but enhances airway inflammation and hyperresponsiveness

The aim of this study was to investigate the role of immunoglobulin E (IgE) in the late phase reaction (LPR) of murine experimental asthma. Our model consisted of an implant of DNP-conjugated, heat-coagulated hen's egg white (DNP-EWI), followed 14 days later by an intratracheal challenge with aggregated DNP-ovalbumin. Airway inflammation was analyzed 48 h after challenge and compared with a similarly immunized group of mice with highly suppressed humoral response due to anti-micro and anti-delta antibody treatment. Total number of cells in the bronchoalveolar lavage (BAL) (with predominance of eosinophils) and EPO activity in the lung homogenate were increased in the DNP-EWI-immunized group compared with immunosuppressed or nonimmunized mice. However, the cellular infiltration and EPO activity observed in the immunosuppressed group were still significantly above those obtained in the nonimmunized group, indicating that inhibition of antibody production did not completely prevent the inflammatory manifestations in BAL and lung. Airway hyperresponsiveness to methacoline was obtained in DNP-EWI-immunized mice, but the respiratory mechanical parameters returned to normal levels in the immunosuppressed group. When these mice were reconstituted with monoclonal anti-DNP antibodies, only IgE, but not IgG1, restored lung inflammation and decreased the conductance of the respiratory system, therefore, increasing hyperresponsiveness. These results indicate that antibodies are not essential for induction of LPR in the lung. However, IgE enhances pulmonary inflammation and hyperresponsiveness.

Use of transcutaneous external pacing during transvenous pacemaker implantation in dogs

The aim of this retrospective study was to evaluate the utility of transcutaneous external pacing (TEP) during transvenous pacemaker implantation in dogs. Eighty-two pacemakers were implanted in 77 dogs because of third-degree atrioventricular block (AVB) (58 cases; 70.7 per cent), sinus node dysfunction (SND) (nine cases; 11.0 per cent), high-grade second-degree AVB (six cases; 7.3 per cent), persistent atrial standstill (PAS) (four cases; 4.9 per cent), post-radiofrequency catheter ablation of the bundle of His (four cases; 4.9 per cent) and vasovagal syncope with atrial fibrillation (one case; 1.2 per cent). TEP was initiated during general anaesthesia after the onset of asystole or profound bradycardia, and stopped when permanent pacing was started. The use of TEP was necessary in 27 cases: 19 cases of third-degree AVB, five of SND, two of PAS and one of vasovagal syncope. External pacing was successful in all but two dogs.

The mechanism of the adjuvant effect of Bordetella pertussis: the substance responsible for the selective enhancement of IgE antibody production

An investigation was made to find out the substance present in <i>B. pertussis</i> responsible for the enhancement of IgE antibody production in guinea pigs. Antigen was injected in guinea pigs along with either ribonucleic acid, deoxyribonucleic acid, lymphocytosis promoting factor or Hpopolysaccharide obtained from <i>B. pertussis</i>. It was concluded that the Hpopolysaccharide is the main active material responsible for the enhancement of IgE antibody production in guinea pigs.

Radiofrequency catheter ablation of accessory pathways in the dog: the Italian experience (2008-2016)

INTRODUCTION

Accessory pathways (APs) in dogs are mostly right-sided, display nondecremental conduction, and mediate atrioventricular reciprocating tachycardias (AVRTs). Radiofrequency catheter ablation (RFCA) is considered the first-line therapy in human patients to abolish electrical conduction along APs.

ANIMALS

Seventy-six consecutive client-owned dogs.

MATERIAL AND METHODS

Retrospective study to describe the precise anatomical distribution and the electrophysiologic characteristics of APs in a large population of dogs and to evaluate long-term success and complication rates of RFCA.

RESULTS

Eighty-three APs were identified in 76 dogs (92.1% with single APs and 7.9% with multiple APs); 96.4% were right-sided, 3.6% left-sided. Conduction along the APs was unidirectional and retrograde in 68.7% of the cases and bidirectional in 31.3%. Accessory pathways presented retrograde decremental properties in 6.5% of the cases. They mediated orthodromic AVRT in 92.1% of the cases and permanent junctional reciprocating tachycardia in 6.5%. In one case, no AVRT could be induced. In 97.4% of dogs, RFCA was attempted with an acute success rate of 100%. In 7.7% of cases, recurrence of the tachycardia occurred within 18 months, followed by a second definitively successful ablation. A major complication requiring pacemaker implantation was identified in 2.6% of dogs.

DISCUSSION

Accessory pathway distribution and electrophysiologic properties in these 76 dogs were similar to previous report. Long-term success and complication rates of RFCA in dogs appeared very similar to results of humans.

CONCLUSION

Radiofrequency catheter ablation of APs can be performed with a high success rate and low incidence of complications.

Determination of PAH in atmospheric particulates in the area of the Italian base in Antarctica: report on monitoring activities during the last three scientific expeditions

Concentrations of polycyclic aromatic hydrocarbons (PAH) in atmospheric particulates have been determined in the frame of the control activities for environmental protection during the VI (1990-1991), VII (1991-1992) and VIII (1992-1993) Italian expeditions in Antarctica. Samples were collected at the four cardinal points at about 200 m from the central area of the Italian scientific base. Data show low levels of the individual PAH (95% in the range 1-50 pg m(-3)) confirming the absence, up to now, of significant contamination from the base. These results could be used as a reference for the assessment of the air pollution due to combustion sources present in the base. Any possible variation in the base's activities in the future should be analysed and evaluated with respect to these findings.

Two biologically different mouse IgG1 antibodies

Isolated mouse antibodies were submitted to affinity chromatography with protein A. Three peaks were obtained: peak I that did not bind to protein A, peak II eluted with 0.5 M NaSCN and peak III eluted with 2.0 M NaSCN. Peak I and peak II contained IgG1 but no detectable IgG2 or IgG3, whereas peak III contained IgG2 and IgG3 but no detectable IgG1. Peak I, but not peak II, showed heat-resistant passive cutaneous anaphylactic (PCA) activity in rats which was absorbed by anti-IgG1 antiserum but not by anti-IgE. Both peak I and peak II showed heat-resistant PCA activity in mice, that was absorbed by anti-IgG1 serum. Peak III showed PCA activity in guinea pigs but not in mice or rats. These findings suggest that mouse IgG1 can be divided into 2 populations that differ in their affinity for protein A and in their PCA activity.

Hemidystonia secondary to acquired toxoplasmosis in a non-immunodeficient patient

We discuss the unusual presentation of acquired toxoplasmosis in a girl with severe and transient hemidystonia as a unique symptom. Serum titres of anti-toxoplasma antibodies increased whereas no specific antibody response in the CSF was observed. While symptomatic drugs were inefficacious, specific anti-toxoplasmosis therapy led to complete and permanent recovery within 2 months.

Neurokinin depletion attenuates pulmonary changes induced by antigen challenge in sensitized guinea pigs

The role of neurokinins in the acute pulmonary response to antigen was studied in guinea pigs that received ovalbumin (50 mg/kg ip) on days 1 and 3 and capsaicin (50 mg/kg sc) on day 21 (OAC); ovalbumin on days 1 and 3 (OA1); capsaicin on day 1 and OA on days 8 and 10 (COA); and ovalbumin on days 8 and 10 (OA2). On day 28, guinea pigs were submitted to ovalbumin aerosol challenge. Maximal values of pulmonary dynamic elastance (Edyn) and pulmonary resistance (RL) were significantly lower in OAC and COA groups compared with OA1 and OA2 groups (P < 0.001). There was no difference between maximal Edyn and RL values obtained in OAC and COA groups. Morphometric analysis of lungs showed significantly (P < 0.05) lower values of contraction index of airways, peribronchial edema, and alveoli over inflation in guinea pigs that received capsaicin compared with intact guinea pigs. Capsaicin treatment did not influence the formation of specific IgG1 anaphylactic antibodies. We conclude that neurokinin depletion results in a decrease in the pulmonary mechanical and inflammatory responses to antigen challenge in sensitized guinea pigs. These effects are observed when capsaicin is given either before or after sensitization.

Failure of insoluble antigens to elicit anaphylactic reactions

Paniculate antigens failed to provoke anaphylactic reaction in both the active systemic and the passive cutaneous forms, in the guinea pig. This seems to indicate that anaphylaxis requires the presence of soluble antigens, which, by crossing the vessel walls can react with sensitized cells located extravascularly.

Homocytotropic and heterocytotropic activity of mouse IgG1 antibodies

Mouse anti-ovalbumin antibodies were isolated by affinity chromatography and fractionated in a column of protein A-Sepharose. Three peaks were obtained: peak I that did not bind to protein A, peak II eluted with 0.5 M NaSCN and peak III eluted with 2.0 M NaSCN. Peak I and peak II contained IgG1 but no detectable IgG2 or IgG3, whereas peak II contained IgG2 and IgG3 but no detectable IgG1. Peak I, but not peak II, showed heat-resistant passive cutaneous anaphylactic (PCA) activity in rats, which was absorbed by anti-IgG1 serum but not by anti-IgE. Both peak I and peak II showed heat-resistant PCA activity in mice, that was absorbed by anti-IgG1. Peak III showed PCA activity in guinea pigs but not in mice or rats. These findings suggest that mouse IgG1 can be divided into 2 populations that differ in physicochemical and biological properties.