X-cephalometric study of different parts of the upper airway space and changes in hyoid position following mandibular fractures / Estudio cefalométrico con rayos X de diferentes partes del espacio de las vías respiratorias superiores y cambios en la posición hioidea tras fracturas mandibulares

OBJECTIVE: This study analyses the different parts of the upper airway space and the changes in hyoid position. The results provide a clinical reference for developing timely and effective treatment programmes for patients with mandibular fractures caused by maxillofacial trauma. METHODS: Standard X-cephalometric measurements of the lateral skull of 210 subjects were taken. The subjects were divided into four fracture groups: condylar, mandibular angle, mandibular body, and parasymphyseal. RESULTS: The radiographs of the mandibular fracture groups were compared with the normal occlusion group to analyse the upper airway space and the changes in hyoid position. Different types of fractures have different effects on the upper airway space. Bilateral mandibular body fracture and the parasymphyseal fracture have a significant influence on the lower oropharyngeal and laryngopharyngeal airway spaces, with serious obstructions severely restricting the ventilatory function ofpatients. CONCLUSIONS: Fractures at different parts of the mandibular structure are closely related to the upper airway and hyoid position.

OBJETIVO: Este estudio analiza las diferentes partes del espacio de las vías respiratorias superiores y los cambios de posición hioidea. Los resultados proporcionan una referencia clínica para desarrollar programas de tratamiento oportuno y eficaz para los pacientes con fracturas de la mandíbula, causadas por trauma maxilofacial. MÉTODOS: Se hicieron mediciones X-cefalométricas estándares del cráneo lateral a 210 sujetos. Los sujetos fueron divididos en cuatro grupos de fractura: ángulo mandibular, condilar, cuerpo mandibular y parasinfisaria. RESULTADOS: Las radiografías de los grupos de fractura mandibular fueron comparadas con el grupo de oclusión normal para analizar el espacio de las vías respiratorias superiores y los cambios de posición hioidea. Diferentes tipos de fracturas tienen diferentes efectos sobre el espacio de las vías respiratorias superiores. La fractura de cuerpo mandibular bilateral y la fractura de parasinfisaria tienen una influencia significativa en los espacios de las vías respiratorias orofaríngea y laringofaríngea inferiores, con serios obstáculos restringiendo severamente la función respiratoria de los pacientes. CONCLUSIONES: Las fracturas en diferentes partes de la estructura mandibular se hallan estrechamente vinculadas a las vías respiratorias superiores y a la posición hioidea.

Pattern of sensitization to common environmental allergens amongst atopic Singapore children in the first 3 years of life.

This study was aimed to investigate the sensitization pattern to a range of common allergens in young Singaporean children. A cross-sectional study involving 75 children aged below 3 years was carried out. They presented between December 1995 and April 2000 with symptoms of asthma, rhinitis, eczema, or food allergy. Their levels of allergen-specific serum IgE to a panel of foods (egg white, milk, soy protein, shrimp, wheat and peanut), pet dander, dust mites and cockroaches were measured with Pharmacia CAP System radioallergosorbent test kits. Serum IgE levels greater than 0.35 kU/l represented a positive result. Four children could not be tested with the complete panel because of insufficient serum. The prevalence of sensitization was highest for cow's milk (45.9%) followed by egg white (38.7%), dust mites Dermatophagoides pteronyssinus (31.4%) and Blomia tropicalis (25.5%). Sensitization to ingested allergens was significantly more prevalent in children aged 1 year or younger than in the older children (70.4% of those below 1 year, and 50% of those aged 1-3 years; p < 0.02). Sensitization to inhaled allergens, such as dust mites, was more likely to manifest as respiratory symptoms (allergic rhinitis and asthma), while ingested allergens were associated with gastrointestinal symptoms and eczema (p < 0.001). It was concluded that infants and young children are at high risk of sensitization to common environmental substances. Allergen avoidance is therefore important even in the very young. The prevalence of sensitization to food allergens is higher compared to inhalant allergens in young children.

The significance and technical aspects of quantitative measurements of inflammatory mediators in allergic rhinitis.

The pathophysiology of allergic rhinitis induced by various inhalant allergens through an IgE mediated mechanism, has been well demonstrated. The participation of many important inflammatory cells and mediators released by these cells in the human nasal allergic reaction provides insight into the relationship between the responsiveness to allergen exposure and nasal symptoms of allergic rhinitis. This paper summarizes our previous studies on some important mediators in the nasal secretions of atopic patients during different phases after nasal allergen challenge and during natural allergen exposure. The microsuction technique proves to be an especially useful and reliable nasal sampling method permitting quantitative analysis of important mediators such as histamine, tryptase, leukotriene C4 and eosinophil cationic protein in nasal secretions. The measurement of these mediators during allergic reactions provides accurate data on the activity of some important inflammatory cells (i.e., mast cells, basophils, and eosinophils) and their responses to therapy.

Inositolphosphoglycan second messengers

The mechanisms by which cellular receptors can elicit different biological responses in a maturation state-dependent manner is one of the central problems in cell differentiation which remains to be resolved. The signals generated are likely to be due to additional (as yet unknown) transmembrane signalling pathways. In addition, the recent observation that a single growth factor receptor can activate a whole family of different putative second messengers and that the combinatorial interactions and stoichiometric ratios between the different messengers determine the resulting biological activities has opened up a whole new area of cell biology. It has been proposed that membrane GPI-anchors may function in signal transduction. We have recently confirmed the presence of a family of inositolphosphoglycan second messengers. Partial structural data suggest that these second messengers are not derived from known GPI membrane anchors and may thus constitute a novel class of non-protein-conjugated GPI