The biology of allergenic domestic mites

Conclusion Since 1990 our knowledge of the biology of domestic mites has increased in a number of areas. Taxonomically, keys that are easier to use by nonacarologists have been made available and should help in clinical studies of mite populations in the home environment. From house dust surveys our understanding of the geographical distribution ofE. maynei andB. tropicalis has progressed. Detailed studies of mite populations in mattresses has clarified the distribution of mites within this habitat, which may eventually aid in targeting control of mites in mattresses. In relation to this, a clearer understanding of the influence of climatic factors on the mattress microhabitat has led to investigations into the potential use of ventilation as a means of domestic mite control. Our increased understanding of the survival of desiccation resistant protonymphs is important in this regard. More information on the biochemistry of mite enzymes has been obtained from studies to characterize potentially allergenic mite enzymes. Finally, the relationship between house dust mites and fungi has been resolved with respect to both nutritional ecology and allergen production. Our progress in all of these areas serves to demonstrate the invaluable contribution that biological research can make to clinical studies of domestic mite epidemiology, allergen production, and control.     

Onset, progression, and plateau of skeletal lesions in fibrous dysplasia and the relationship to functional outcome.

Most lesions in FD and their attendant functional disability occur within the first decade; 90% of lesions are present by 15 years, and the median age when assistive devices are needed is 7 years. These findings have implications for prognosis and determining the timing and type of therapy. INTRODUCTION: Fibrous dysplasia of bone (FD) is an uncommon skeletal disorder in which normal bone is replaced by abnormal fibro-osseous tissue. Variable amounts of skeletal involvement and disability occur. The age at which lesions are established, the pace at which the disease progresses, if (or when) the disease plateaus, and how these parameters relate to the onset of disability are unknown. To answer these questions, we performed a retrospective analysis of a group of subjects with FD. MATERIALS AND METHODS: One hundred nine subjects with a spectrum of FD were studied for up to 32 years. Disease progression was assessed in serial (99)Tc-MDP bone scans by determining the location and extent of FD lesions using a validated bone scan scoring tool. Physical function and the need for ambulatory aids were assessed. RESULTS: Ninety percent of the total body disease skeletal burden was established by age 15. Disease was established in a region-specific pattern; in the craniofacial region, 90% of the lesions were present by 3.4 yr, in the extremities, 90% were present by 13.7 yr, and in the axial skeleton, 90% were present by 15.5 yr. Twenty-five of 103 subjects eventually needed ambulatory aids. The median age at which assistance was needed was 7 yr (range, 1-43 yr). The median bone scan score for subjects needing assistance was 64.3 (range, 18.6-75) compared with 23.1 (range, 0.5-63.5) in the unassisted subjects (p < 0.0001). Among subjects needing assistance with ambulation, 92% showed this need by 17 yr. CONCLUSIONS: The majority of skeletal lesions and the associated functional disability occur within the first decade of life. The implication is that the window of time for preventative therapies is narrow. Likewise, therapeutic interventions must be tailored to where the patient is in the natural history of the disease (i.e., progressive disease [young] versus established disease [older subjects]). These findings have implications for prognosis, the timing and type of therapy, and the development of trials of new therapies and their interpretation.     

The myth of the final hazard assessment

Hazard assessment is a basic tool used in the evaluation and regulation of chemicals, but in spite of this there are many different interpretations of the scope and function of a hazard assessment. Starting from a discussion of the essential elements and conceptual frames involved, an attempt is made to identify the sources of uncertainty that are inherent in a hazard assessment. Problems identified include unambiguous identification of the chemical source, the routes of exposure, and the possible targets to be considered. Inadequacies in effects data are frequent, but unlike many of the other sources of uncertainty, these are often compensated for by the use of safety factors when setting quantitative limits for human or environmental exposure. The inherent uncertainties in the process make periodic revisions of any hazard assessment process inevitable, as new knowledge on routes of exposure and targets becomes available.     

An analysis of fluid loss during transcervical resection of submucous myomas

Objective: To determine the contribution of several variables to fluid loss during transcervical resection of submucous myomas.Design: An observational study using multiple linear regression analyses.Setting: A university-affiliated training hospital and a university department of clinical epidemiology and biostatistics.Patient(s): Patients with submucous myomas.Intervention(s): Transcervical resection of submucous myomas and monitoring of fluid loss.Main Outcome Measure(s): Patient age, uterine enlargement, treatment with GnRH analogues or 8-ornithine-vasopressin, type of anesthesia, number of myomas, intramural extension of the myoma (type of myoma), and operating time were tested as variables.Result(s): Only intramural extension of the myoma and operating time were obviously related to fluid loss. For the other variables, such a relation was weak at best. The relation between fluid loss and operating time was not modified by any of the other variables.Conclusion(s): Because fluid loss is an important limiting factor in the transcervical resection of submucous myomas, special attention should be paid to reduction of the operating time and preoperative assessment of the intramural extension of the myoma to guide appropriate patient selection.     

Induction of type II collagen-specific antibody production in blood lymphocyte cultures of rhesus monkeys (Macaca mulatta) with collagen-induced arthritis using the immobilized native antigen.

Peripheral blood mononuclear cells (PBMC) from Rhesus monkeys previously immunized with bovine type II collagen to induce arthritis were cultured with the same antigen. Because the native protein is poorly soluble in culture medium a heating step is often used. The antigen in this form induced PBMC proliferation, but epitopes for the induction of antibody production and arthritis were lost. To keep the native protein intact it was coated on affigel beads. With the immobilized antigen specific antibody production could be induced.     

Staging and prognostic factors in carcinoma of the base of the tongue.

During the period 1966-1985, 66 patients were submitted for curative treatment of a carcinoma of the base of the tongue in the Netherlands Cancer Institute. Treatment consisted of radiotherapy (59 patients), surgery and post-operative radiotherapy (4 patients) and surgery alone (3 patients). Patients were staged according to the UICC (1982) and UICC (1987)/AJCC (1988) criteria. Regrouping by the latter system caused enlargement of the N2-group and of stage IV. The crude 5-year survival was 22%, the 5-year tumour control was 36% and the locoregional control was 47%. The most important prognostic factors for the tumour-free interval are the T-category (P = 0.01) and stage grouping (UICC 1982) (P = 0.022). The same factors predict the locoregional control (P = 0.005 and 0.02 respectively). Crude survival is lower in smokers, and in patients in poor general condition (P = 0.04 and 0.007 respectively).