Immunoglobulin E reactivity of native Blo t 5, a major allergen of Blomia tropicalis

BACKGROUND: Blo t 5 is a major allergen of Blomia tropicalis and its complementary DNA (cDNA) has been expressed in both prokaryotic and eukaryotic expression systems. Although the recombinant Blo t 5 has been well characterized, relatively less is known about its native counterparts and the allergenicity comparison of the native and recombinant Blo t 5 allergens has not been reported. OBJECTIVE: The aims of this study are to characterize the native counterpart of Blo t 5, and compare the allergenicity of native and recombinant Blo t 5 by in vivo and in vitro assays. METHODS: Native Blo t 5 were purified by immuno-affinity chromatography and characterized by proteomic means. The allergenicity of the allergen was evaluated by skin prick tests, human IgE ELISA, ELISA inhibition and histamine release assays. RESULTS: Native Blo t 5 consists of at least five distinct isoforms, ranging from pI 3 to 5.5. Allergenicity assessment of recombinant and native Blo t 5 based on skin reaction, IgE-binding capacity and histamine release in allergic individuals indicated that there was a good correlation between both forms of Blo t 5 in general. However, data from IgE ELISA inhibition assay revealed the presence of additional unique IgE epitopes in native Blo t 5. CONCLUSIONS: At least five distinct isoforms of Blo t 5 have been identified. Comparative assessment of native and recombinant Blo t 5 revealed that the allergenicity of these two forms was similar but not completely identical suggesting that the various isoforms of native Blo t 5 may exhibit additional unique IgE epitopes.     

Sonographic features of anal atresia at 12 weeks.

Anorectal atresia results from abnormal development of the anorectal septum. Prenatal diagnosis is difficult but the condition may be suspected by the sonographic demonstration of a dilated colon. We present the sonographic features of a fetus with anal atresia and a ventricular septal defect at 12 weeks of gestation. This case illustrates that a dilated colon may be present in association with fetal anal atresia as early as 12 weeks.     

Viewpoint: Are doctors responsible for the increase in allergic diseases?

There is no exact explanation for the increase in allergic diseases that occurred since the last two decades. An increased allergen exposure and/or a decreased bacterial load cannot explain the phenomenon completely. Other causal factors that rose at the beginning of the 1980s must be taken into consideration. Important changes at that time in our management of children were the worldwide switch from aspirin to paracetamol, the introduction of broad-spectrum antibiotics such as cephalosporins and the advice to avoid dust and pets in newborns from allergic families. General application of these new approaches, in itself or in combination, might be responsible, at least in part, for the increase of allergic diseases in children.     

Further characterization of Marek's disease virus-infected lymphocytes. I. In vivo infection

Previous reports from this laboratory identified bursa-derived lymphocytes (B cells) and non-B cells as the predominant cell types respectively involved in the early cytolytic and subsequent latent infection of chickens with Marek's disease virus (MDV). It was not known whether these differences were qualitative or quantitative or if the method for detection of latent infection (viral antigen production after 48 h of in vitro cultivation) was sensitive enough. To further define the cells involved in the various phases of MDV infection, we used monoclonal antibodies which specifically react with B cells, or T cells, or la-antigen-bearing cells. Dual fluorescence tests to detect surface markers and viral internal antigen (VIA) were conducted with infected spleen cells freshly collected from MDV-infected chickens or after in vitro cultivation of those cells. The same antibodies were also used for a rosetting procedure to yield fractions enriched or depleted of T cells, B cells or la-bearing cells. These were examined directly for viral DNA by in situ hybridization or dot blot DNA hybridization and for VIA cultivation. We learned that infected T cells also comprise part of the early cytolytic phase of MDV infection but constitute a minority population (approximately 2-3%) compared to B cells (83-92%) at 3 or 4 days post infection. Latently infected cells were definitively identified as mostly la-bearing T cells, although a few (2-4%) were B cells. Prior to in vitro cultivation, latently infected cells apparently had insufficient viral DNA for detection by in situ hybridization, but the more sensitive dot blot procedure revealed viral DNA in fractions later found positive by VIA expression after in vitro cultivation. Viral DNA replication in latently infected cells apparently had occurred after 48 h cultivation because in situ hybridization detected infected cells at that time. Treatment of cell cultures with iodo-deoxyuridine, 12-O-tetradecanoyl phorbol-13-acetate or n-butyrate failed to increase the number of spleen cells which expressed VIA.     

Frequency, satisfaction and quality dimensions of perceived parent-adolescent communication among Chinese adolescents in Hong Kong

Chinese adolescents (N=88) responded to instruments measuring three dimensions of parent-adolescent communication (frequency of parent-adolescent communication, satisfaction with parent-adolescent communication and quality of parent-adolescent communication) and adolescent psychological well-being (mastery and life satisfaction). Results showed that Chinese adolescents perceived sharp distinction between fathers and mothers in terms of these three dimensions: fathers were perceived to have less communication with adolescents than did the mothers; the satisfaction and quality ratings for father-adolescent communication were lower than those based on mother-adolescent communication. Results also showed that relative to the frequency of parent-adolescent communication, satisfaction with and quality of parent-adolescent communication were more strongly related to adolescent psychological well-being. Although global quality of father-adolescent communication and mother-adolescent communication were related to adolescent life satisfaction, global quality of father-adolescent communication appeared to have a stronger relationship with adolescent mastery than did mother-adolescent communication.     

Alcohol use and abuse amongst adolescents in Hong Kong

This paper discusses alcohol use and abuse amongst adolescents in Hong Kong on the basis of a thorough literature review of official statistics and empirical research. The review highlights four major observations. Firstly, the alcohol culture of Hong Kong adolescents is basically positive and social-oriented. The existing legal constraint on the use of alcohol by those aged under 18 seems to exist in name only. Secondly, the past decade has seen a rising trend in alcohol use by adolescents, both in terms of those who have ever consumed it and those who do so currently. Thirdly, several demographic variables associated with alcohol use have been identified, including gender, age, and school mode. Fourthly, peer interactions (such as involvement in organized criminal groups) and family factors (such as lack of maternal support) are also related to alcohol use in young people. The paper closes by making some observations on the gaps in the research and sets forth some ideas for future policy development.     

Adolescent developmental issues in Hong Kong: Relevance to positive youth development programs in Hong Kong

Several adolescent developmental issues and problems in Hong Kong are examined in this paper. First, the changing adolescent substance abuse patterns are described. Second, although the overall youth crime trend was relatively stable in the past decade, shoplifting and stealing crimes deserve our concern. Third, adolescent mental health problem is a growing problem. Fourth, statistics show that unhealthy life styles, such as smoking, early sex and moral confusion are issues of concern. Fifth, the proportion of adolescents experiencing economic disadvantage has increased. Sixth, youth unemployment and non-engaged youth are growing problems when the economy of Hong Kong is undergoing re-structuring. Seventh, family and parenting problems in families with adolescents deserve our attention. Finally, the Social Development Index showed that the development of young people has gradually deteriorated in the past decade. These adolescent issues and problems provide useful pointers for designing the positive youth development program financially sponsored by the Hong Kong Jockey Club Charities Trust.     

Extraperitoneal approach for closure of epithelized enterocutaneous fistulas following late removal of jejunostomy tube

Epithelized enterocutaneous fistulas will form if feeding jejunostomy tubes are kept for a lengthy period. Such fistulas may not close spontaneously, and thus surgical closure will be necessary. An intraperitoneal surgical approach is most commonly used but is often difficult and a major undertaking. A novel, simple, and safe technique to close such enterocutaneous fistulas extraperitoneally under local anesthesia is devised.