Change of bronchial hyperresponsiveness in asthmatic children.

INTRODUCTION: Bronchial hyperresponsiveness (BHR) is a factor in predicting bronchial asthma independently of inflammation markers. OBJECTIVE: The aims were to determine the frequency and important predictive facts of BHR and the effect of prophylaxis by Global Initiative for Asthma (GINA) and National Asthma Education and Prevention Program (NAEPP) on BHR in asthmatic children. METHODS: BHR in 106 children was evaluated by the bronchoprovocation test with methacholine. RESULTS: The prevalence rate of symptomatic BHR is 18% for crucial point of PC20 = 4.1 +/- 3.03 mg/ml and PD20 = 3.22 +/- 2.59 micromol methacholine. On average asthmatic children express moderate BHR, which persists even two years after administering prophylaxis. After two years bronchial reactivity is significantly smaller, the change of FEV1 is significantly smaller, the velocity of change of slope dose response curve (sDRC) is faster and the provocative concentration of methacholine that causes wheezing is 2-3 times lower. A mild sDRC shows milder bronchoconstriction after two years. The fast change of bronchial reactivity in 41% of asthmatic children is contributed to aero-pollution with sulfur dioxide and/or, possible insufficient and/or inadequate treatment during two years of administering prophylaxis. A simultaneous effect of allergens from home environment and grass and tree pollens and of excessive aero-pollution on children's airways is important in the onset of symptomatic BHR. After two years of treatment by GINA and NAEPP children do not show asthma symptoms or show mild asthma symptoms, however bronchial sensitivity remains unchanged. CONCLUSION: Optimal duration of anti-inflammatory treatment in asthmatic children who show moderate bronchial hyperresponsiveness should be longer than two years.

[Position of anticholinergic drugs in the treatment of childhood asthma].

Anticholinergic drugs block muscarinic effect of acetylcholine on the receptors of postjunctional membranes and so inhibit the answer of the postganglionic parasympathetic nerve. The loss of M2 muscarinic receptors function occurs in asthmatics and it contributes to bronchial hyperresponsiveness and it is not a chronic feature of asthma, instead it characterizes asthma exacerbation. The loss of M2 muscarinic receptor function in children and adults happens during antigen bronchoprovocation or during exposition of asthmatics to ozone. After inhalation, ipratropium bromide (IB) can be found in a small quantity in circulation and it links less readily to muscarinic receptors on airway smooth muscles as related to its absorption after intravenous application. In the stepwise approach of asthma inhaled anticholinergics is recommended if the symptoms of the disease cannot be adequately controlled by a regular inhalation of antiinflammatory drugs with beta2-agonist and oral steroids. The improvement of the airway inspiratory capacity is more elevated than the improvement of FEV1 after inhalation of IB. IB has similar effect as salbutamol and it is recommended to control a stable chronic obstructive disease. During our numerous investigations and up-to-date experience in the usage of 5-7 microg/kg/body mass of IB repeated every 4-6 hours in combination with salbutamol, we did not notice adverse effects of the drug in infants. IB is recommended for hospital treatment of children.

[Rotavirus gastroenteritis].

Rotavirus is the main etiological agent that causes severe diarrheal diseases in newborns and young children up to two years. Every year, about one million children around the globe die of dehydration caused by Rotaviruses. The problem is even bigger in underdeveloped and developing countries. The results of our 18-month research, in the town Kragujevac and its surrounding area from December 1998 to May 2000 indicate that viruses are an important factor in the etiology of the acute diarrheal diseases in our population. In 124 children, aged 0 to 5, with the acute diarrheal diseases treated at the Pediatric clinic HMC "Kragujevac", viruses were the causes in 27% of the time. The Rotavirus belongs to the family Reoviridae. The infections caused by rotaviruses may be detected around the world. The incidence rate is higher in developed countries. The infection is transmitted orally. The entry of the Rotavirus infection is the upper part of the small intestine. The clinical picture is specific. The disease usually lasts four to seven days. The fastest diagnostic method is direct detection of viruses using the electronic microscope. The agglutination tests ELISA and LATEX are used for the examination of numerous samples. Only symptomatic treatment is required. High morbidity and mortality rates in developing countries are the reason to prevent the Rotavirus disease by active immunization.