Clinical efficacy of montelukast sodium in treating infantile wheezing.

OBJECTIVES: The efficacy and safety of a single-dose of Montelukast sodium for treating virus-related infantile wheezing are investigated in this study. PATIENTS AND METHODS: A prospective, open, randomized, controlled study was carried out on 595 cases of infants who exhibited wheezing after a respiratory syncytial virus infection. Treatment with Montelukast sodium was provided over the course of 12 weeks. The clinical efficacy of Montelukast sodium was determined based on the clinical symptom score, tidal breathing lung function, and short-acting bronchodilator usage, as well as infantile asthma diagnosis rate change at the 4th and 12th week after the administration of the treatment. The adverse reactions were also observed, and a control group was set. The mean age of the 595 patients with infantile wheezing was 10.82 months ± 4.22 months. Among these patients, 45.9% (273 out of 595) had a family history of asthma, 30.6% (182 out of 595) had allergic rhinitis, 23.9% (142 out of 595) increased peripheral blood eosinophilia, 6.1% (36 out of 595) exhibited total IgE increase, 40.0% (238 out of 595) had a recurrent history of wheezing, and 64.0% (381 out of 595) had a family history of eczema. RESULTS: After 12 weeks of treatment, the clinical symptom scores significantly improved. Significant differences in the cough, wheezing, and motility scores were observed before and after the treatment (p < 0.05). TPTEF/TE and VPEF/VE significantly improved (p < 0.05) after the treatment. The asthma diagnosis rate was 9.6% (57 out of 595). At four weeks after treatment, various indicators correspondingly improved. Twenty-nine (4.9%) patients exhibited adverse reactions, 55.2% exhibited excitation, 20.7% suffered from insomnia, 10.3% had headaches, 3.4% had erythra, 3.4% suffered from abdominal pain, and 3.4% exhibited an increased glutamic-pyruvate transaminase level. The symptoms of eczema were relieved to some extent, and the symptoms of rhinitis became less serious. Significant differences were observed in the number of wheezing attacks, annual number of days hospitalized, annual number of days when ß2AG was utilized, and lung function improvement (p < 0.05). CONCLUSIONS: Montelukast sodium is clinically effective in treating virus-related wheezing, and clinical application for 4 weeks to 12 weeks can effectively relieve the symptoms of wheezing, improve lung function, and reduce the incidence rate of infantile asthma. Montelukast sodium also causes few adverse reactions.

N-glycosylation of the premembrane protein of Japanese encephalitis virus is critical for folding of the envelope protein and assembly of virus-like particles.

Premembrane (prM) and envelope (E) proteins, the major structural proteins of Japanese encephalitis virus (JEV) each contain single potential N-glycosylation site. In this study, the role of N-glycosylation of these proteins on their folding and activity were investigated. Three mutant prM and/or E (prM-E) genes lacking N-glycosylation sites were generated by site-directed mutagenesis. The effects of the N-glycan on folding, secretion and cytotoxicity of mutant proteins were determined by comparison with their wild type (wt) counterparts. Removal of N-glycan from the prM protein resulted in a complete misfolding of the E protein and failure to form virus-like particles (VLPs). A similar removal of N-glycan from the E protein led to a low efficiency of its folding and VLPs formation. The secretion and cytotoxicity of the E protein was also markedly impaired in case the glycosylation sites in the prM or E or both proteins were removed. These results suggest that the N-glycosylation of the prM protein is critical to the folding of the E protein, which makes it pivotal in the cytotoxicity of JEV particles and their production.