Activation of basophils by the double-stranded RNA poly(A:U) exacerbates allergic inflammation.

BACKGROUND: It is commonly acknowledged that asthma is exacerbated by viral infections. On the other hand, basophil infiltration of lung tissues has been evidenced postmortem in cases of fatal disease, raising the question of a possible link between these two observations. OBJECTIVES: Herein, we addressed the relationship between asthma exacerbation by viral infection and basophil activation and expansion by investigating how stimulation with the dsRNA polyadenylic/polyuridylic acid [poly(A:U)] affected basophil activities and recruitment in an allergic airway inflammation model. METHODS: The effect of dsRNA on basophils was assessed by measuring the cytokine levels produced upon stimulation. We used an OVA-induced experimental model of allergic asthma. Airway hyperreactivity, recruitment of infiltrating cells, and cytokine production were determined in the lung of mice having received poly(A:U), as compared with untreated controls. The exacerbating effect of basophils was assessed both by adoptive transfer of poly(A:U)-treated basophils and by their in vivo depletion with Ba103 antibody. RESULTS: We found that in vitro treatment with poly(A:U) increased basophil functions by inducing TH 2-type cytokine and histamine production, whereas in vivo treatment increased peripheral basophil recruitment. Furthermore, we provide the first demonstration for increased infiltration of basophils in the lung of mice suffering from airway inflammation. In this model, disease symptoms were clearly exacerbated upon adoptive transfer of basophils exposed to poly(A:U), relative to their unstimulated counterpart. Conversely, in vivo basophil depletion alleviated disease syndromes, thus validating the transfer data. CONCLUSIONS: Our findings provide the first evidence for airway inflammation exacerbation by basophils following dsRNA stimulation.

[Amebic abscess of the liver: ultrasound guided puncture]. / Abcés amibiens du foie: ponction écho-guidée.

The aim of this study is to present the results of ultrasound-guided needle aspiration in amoebic abscess of the liver in 1289 patients. Out of 1512 patients hospitalized from 1990 to 1995 for an amoebic abscess of the liver, 1289 (83.6%) were treated by this approach. The abscesses of less than 40 mm (8.9%) were treated medically, and those of more than 170 mm (0.6%) were operated on. The abscesses with peritonitis (5.2%) were also operated on. A treatment with metronidazole or dehydroemetin was associated with the surgical treatment or with the aspiration of the abscess. There was no death. A second aspiration was necessary in 24.9% of the patients, and a third one in 9.4%. Three complications were observed, two hemorrhages and one fistula. Nine patients had a recurrent abscess after their discharge from hospital. Four failures were observed in patients with abscesses of more than 170 mm in diameter. Results were considered as good in 1273 patients (98.7%). These results suggest that in amoebic abscess of the liver with a diameter between 40 and 170 mm, aspiration associated with amoebic treatment may be the standard treatment. Smaller abscesses usually recover with medical treatment alone, and greater abscesses need surgical drainage.