Air pollutants enhance rhinoconjunctivitis symptoms in pollen-allergic individuals.

BACKGROUND: Little is know about the relation of airborne pollen allergens to nasal and ocular symptoms in combination with air pollutants. OBJECTIVE: The hypothesis was that air pollutants exacerbate allergic symptoms of the nose and eyes during the pollen season. In addition, the use of allergen measurements instead of pollen counts should be tested. METHODS: Fifteen pollen-allergic, nonsmoking subjects with weak reactivity of the airways recorded rhinoconjunctival symptoms and medication every morning and evening throughout the pollen season. Symptoms were compared with air pollutants (nitrogen oxide [NOx], particulate matter smaller than 10 microm, and ozone) and birch and grass pollen counts or, alternatively, to airborne birch and grass allergens determined using ELISA-techniques. A multiple linear regression model was used which controlled for autocorrelation of the residuals of the time series (Cochrane-Orcutt approach). This model was applied to each subject individually, followed by calculations of summary scores for the group. RESULTS: Air pollution levels were moderate, often meeting air quality standards. Effect estimates (increase of score with 10-fold increase of concentration) were NOx = 1.06, P < 0.01; ozone = 1.59, P < 0.01; and pollen = 0.48, P < 0.001. Using allergen concentrations instead of pollen counts resulted in similar effect estimates. Using particulate matter smaller than 10 microm instead of NOx gave comparable but less consistent results. CONCLUSIONS: Symptoms were related to moderate levels of pollutants, suggesting that rhinoconjunctival tissue is very sensitive to irritant stimuli during an ongoing allergic inflammation, and that susceptibility toward allergens might be increased in areas with increased levels of air pollutants. Allergen measurements seem equally usable as pollen counts to investigate rhinoconjunctivitis.

A retrospective study of combined fixed-removable reconstructions with their analysis of failures.

The survival rate and the reasons for failures of 130 combined fixed-removable reconstructions (CFR), incorporated in 112 patients, were assessed. Each CFR reconstruction was classified depending on its attachments: 76 reconstructions were attached with rigid, precise attachments, and constituted the rigid group; 54 reconstructions were attached with either semi-precision or individual attachments and were defined as the semi-rigid group. Of the 130 reconstructions, 41 were determined as complete successes, 39 as partial successes and 50 as failures, leading to 37 major repairs and to 13 new reconstructions. Three reconstructions failed due to technical reasons, 36 due to biological reasons and for 11 reconstructions, both categories of reasons were responsible for their failure. In total, technical reasons were counted 15 times in comparison to 73 biological reasons for those 50 failed reconstruction, with 29 fractured abutment teeth as the most common biological reason. Within the rigid group, 45 failed reconstructions were observed, whereas within the semi rigid group only 5 failures occurred, leading to an 8-year survival estimate (+/- SD) of 30.1% (+/- 6.9%) for the rigid group and 93.1% (+/- 3.9%) for the semi rigid group. Beside the attachment type, the anatomy of the partially edentulous tooth arch in form of the free-end situation and the dentate opposing jaw were identified as risk factors.

Correlation of imaging and clinical features in the assessment of mandibular invasion of oral carcinomas.

The detection in the mandible of early local spreading of adjacent primary malignancies poses a difficult problem. A survey of 60 patients suspected of carcinomatous mandibular infiltration was undertaken, and the most important clinical and imaging data were studied. Tumor localization and bone scintigraphy proved to offer the most important predictive power. A decision tree and a logistic regression model which determines a score function combining these characteristics were designed. This decision tree improves the sensitivity and specificity of the preoperative assessment and provides the surgeon with an algorithm for the accurate estimation of early mandibular invasion.

Behaviour of small inhibitory interneurons in early postnatal mouse cerebellar microexplant cultures: a video time-lapse analysis.

The aim of this work was to investigate how the environment of the neuropil determines the positioning and differentiation of neurons that are postsynaptic to them. We investigated how stellate and basket cells, the small inhibitory interneurons of the cerebellar cortex, find their perpendicular orientation to the direction of fasciculated granule cell axons. Cultures of early postnatal mouse cerebellar microexplants showing this cellular behaviour in vitro were analysed by video time-lapse cinematography and evaluated by morphometry. The small interneurons were first detectable when they migrated, intermingled with granule cells, away from the explant along the radial fascicles of granule cell neurites. During migration some cells suddenly changed their orientation by extending neurites in perpendicular orientation to the radial fascicles. These cells were all GABA-immunoreactive and expressed the cytoskeletal markers tau in the thin axon-like process and MAP2 in the thicker dendrite-like arborizations at the opposite pole of the cell body. After having translocated in perpendicular orientation, these neurons were again able to turn back to move along the radial neurite bundles to another position. Furthermore, while in perpendicular orientation, the processes of these cells repelled each other upon contact of their growth cones, leading to equal spacing between the cell bodies with time in culture.

Androgen and estrogen effect on guinea pig seminal vesicle muscle: a combined stereological and biochemical study.

A combined electron microscopic stereological and biochemical study of the smooth muscle cells of guinea pig seminal vesicles was performed in intact, castrated, castrated and dihydrotestosterone- or estradiol-treated adult animals. Castration led to cell atrophy as determined stereologically by a decreased single cell volume and biochemically by no change in DNA content coupled with an increase in the DNA concentration. Treatment of castrates with dihydrotestosterone restored both the stereological and biochemical parameters of the cell size to slightly supranormal levels. The estrogen-induced increase in muscle weight and DNA content appeared to be due only to hyperplasia of muscle cells and not to a proliferation of fibroblasts or to infiltration by inflammatory cells. In all treatment groups, including the estrogen-treated castrates, more than 95% of the cells in the tissue were smooth muscle cells, and there was no evidence that polyploidy contributed to changes in DNA levels. In addition, in the estrogen-treated muscles, DNA concentration remained high, and the stereologically determined cell size remained low. Therefore, both morphological and biochemical evidence indicate that androgen induces hypertrophy, whereas estrogen induces hyperplasia of muscle cells. The correction of stereological and biochemical data validates the application of stereological cell size determination for smooth muscle cells in organs that hardly can be separated into stromal and epithelial components; eg, the prostate.