Vitamin E effect in a rat model of toluene diisocyanate-induced asthma

Background and aim

The aim of the study was to evaluate vitamin E effect upon oxidative stress associated with toluene −2, 4-diisocyanate (TDI)-induced asthma in rats.

Methods

The five study groups were: control, vehicle, TDI, vehicle+E, TDI+E. TDI animals were sensitized by nasal administration of TDI 10% (5μl/nostril) between days 1–7 and 15–21. Between days 22–28 groups TDI+E and vehicle+E rats received vitamin E (50 mg/kg, i. v.), and control, vehicle and TDI groups received saline solution. On day 29 the rats were challenged by intranasal application of 5% TDI (5 μl/nostril). On day 30 blood, BALF and lung biopsy were harvested. Oxidative stress tests were malondialdehyde (MDA), protein carbonyls (PC), total thiols (tSH), 1,1-diphenyl-2-picryl hydrazyl (DPPH) and reduced glutathione (GSH).

Results

TDI sensitization increased oxidative stress systemically, but also locally in the respiratory airways and lung tissue. There was an increase of MDA and PC formation associated with a deficiency of the antioxidant defense reflected by DPPH decreases. There were no differences between systemic and local lung concentrations of oxidized molecules.

After vitamin E treatment oxidative stress was reduced mostly due to serum, BALF and lung tissue GSH and DPPH increase.

Conclusion

The study showed that in rat TDI-induced asthma there was oxidative stress caused by increased ROS production and antioxidants deficiency, and vitamin E reduced ROS production and improved antioxidant defense.

524 Reccurent Wheezing in Childhood—Is It Always Asthma?

Background

Clinical presentation of the bronchial obstruction in children is most often highly suggestive of bronchiolitis, recurrent wheezing or asthma.

Methods

We present the cases of 2 patients diagnosed with recurrent bronchiolitis and asthma, non-responsive to treatment.

Results

The first patient, a 9-year-old boy presented wheezing, non-productive cough, dyspnea, aquous rhinorrhea, sneezing and nasal itching interpreted as allergic asthma associated to allergic rhinitis as he was sensitized to house-dust mites and dog. A treatment with inhaled corticosteroids and antihistamine was prescribed with little improvement of asthma symptoms. Six months later the patient presented for vomiting and productive cough. Thoracic ultrasound suggested achalasia, diagnosis confirmed through esophageal manometry and barium swallow. Surgical treatment led to resolution of asthma-like symptoms with persistence of a mild intermittent rhinitis. In the second case, a female patient presented 2 episodes of uncomplicated bronchiolitis during the 6th and the 7th month of life and a 3rd episode of bronchiolitis complicated with pneumonia during the 8th month of life. When admitted for the 3rd episode, she presented an oxygen saturation of 91% in ambient air. Thoracic ultrasounds oriented the diagnosis towards a diaphragmatic hernia, confirmed through barium swallow and barium enema. The surgical treatment of the hernia determined the resolution of respiratory symptoms. Unfavourable clinical course, despite correct treatment in both cases required additional investigations which finally led to the correct diagnosis and treatment.

Conclusions

For the differential diagnosis of non-responsive bronchial obstruction in children, one must think to digestive diseases. Ultrasound was the elective non-invasive method in diagnosing our cases.