[Epidemiological analysis of childhood asthma in Yichang City, China].

OBJECTIVE: To study the prevalence, epidemiological characteristics, and risk factors for childhood asthma in Yichang City, China and to collect evidence for the early diagnosis and preventive treatment of asthma. METHODS: Preliminary screening questionnaires were distributed to more than 90% of children in 5 kindergartens, 10 primary and secondary schools, and 5 communities in Yichang City to detect children with suspected asthma. These surveyed children were selected by cluster random sampling. A further questionnaire survey was conducted for suspected cases. Meanwhile, a similar number of sex- and age-matched non-asthmatic children were selected for the case-control study. Information from returned questionnaires was entered into a database for statistical analysis. RESULTS: A total of 11 000 questionnaires were distributed, and 10 456 (95.1%) questionnaires were returned. The prevalence rate of asthma among children in Yichang was 3.47%, significantly higher in boys than in girls (P<0.05). A total of 107 out of 363 children with asthma had a history of drug allergy, and 152 cases had a family history of allergy. The majority of asthmatic children had irregular onset-prone seasons and hours. Respiratory tract infections were the most common trigger of asthma attacks, accounting for 93.1% of all onsets; family history of allergy, history of early use of antibiotics, history of housing renovation, and history of passive smoking were the major risk factors for asthma. CONCLUSIONS: Prevention of respiratory tract infections may reduce the frequency of asthma attacks; reducing the use of antibiotics during early childhood, decreasing the frequency of housing renovation, and advocating for smoking cessation among parents have preventive effects on asthma.

Exogenous agmatine has neuroprotective effects against restraint-induced structural changes in the rat brain.

Agmatine is an endogenous amine derived from decarboxylation of arginine catalysed by arginine decarboxylase. Agmatine is considered a novel neuromodulator and possesses neuroprotective properties in the central nervous system. The present study examined whether agmatine has neuroprotective effects against repeated restraint stress-induced morphological changes in rat medial prefrontal cortex and hippocampus. Sprague-Dawley rats were subjected to 6 h of restraint stress daily for 21 days. Immunohistochemical staining with beta-tubulin III showed that repeated restraint stress caused marked morphological alterations in the medial prefrontal cortex and hippocampus. Stress-induced alterations were prevented by simultaneous treatment with agmatine (50 mg/kg/day, i.p.). Interestingly, endogenous agmatine levels, as measured by high-performance liquid chromatography, in the prefrontal cortex and hippocampus as well as in the striatum and hypothalamus of repeated restraint rats were significantly reduced as compared with the controls. Reduced endogenous agmatine levels in repeated restraint animals were accompanied by a significant increase of arginine decarboxylase protein levels in the same regions. Moreover, administration of exogenous agmatine to restrained rats abolished increases of arginine decarboxylase protein levels. Taken together, these results demonstrate that exogenously administered agmatine has neuroprotective effects against repeated restraint-induced structural changes in the medial prefrontal cortex and hippocampus. These findings indicate that stress-induced reductions in endogenous agmatine levels in the rat brain may play a permissive role in neuronal pathology induced by repeated restraint stress.