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Notes: A new, very high rate dry etching system based on the plasma jet principle is presented. In this device the active gases are fed into the processing vacuum chamber through a small 0.5 mm i.d. nozzle. By applying radio frequency power (13.56 MHz) a hollow cathode discharge is created inside the nozzle. This discharge will be very intense and effective in dissociating the gas mixture used for reactive etching. A jet stream of radicals will be formed. By placing a silicon substrate in front of this jet stream it is possible to perform very high rate reactive etching of silicon. Etch rates as high as 0.1–0.2 mm/min can be easily obtained. It is demonstrated that the etch rate and the width of the etching crater are sensitive to different processing conditions. The width of the etching crater may be smaller than the diameter of the nozzle exit under certain conditions.

Notes: The electrical, optical, and mechanical properties of a compound film depend strongly on the composition of the film. Therefore, it is interesting to study a wide variety of compositions of many new compound materials. Reactive sputtering is a widely used technique to produce compound thin films. With this technique it is possible to fabricate thin films with different compositions. However, it has not yet, to any great extent, been possible to predict the composition of the sputtered film. In this article we will present a model that enables us to predict both sputtering rate and film composition during reactive sputtering. The results point out that there exists a very simple linear relationship between processing parameters for maintaining constant thin-film composition in the reactive sputtering process. Based on these results, it is possible for the first time to combine information of both sputtering rate and film composition into the same graphical representation. Access to this new and simple graphical representation may eliminate much of the "trial and error'' work that earlier has been associated with the reactive sputtering process.

Notes: Mast cell degranulation, and the subsequent recruitment of infiltrating inflammatory cells, such as eosinophils, into the nasal mucosa has long been considered the most important model to explain allergic rhinitis. Several studies show a decrease in the number of eosinophils and possibly also mast cells during local corticosteroid treatment. Over the last decade, a new model to explain allergic inflammation has evolved. In this model, Langerhans’cells and T-cells play an important role. Langerhans’cells possess a high affinity receptor for IgE. In patients with allergic rhinitis, allergen provocation results in stimulation of T-cells by the IgE-positive Langerhans’cells. The T-cells produce a number of cytokines which stimulate IgE production as well as the inflammatory reaction. The number of T-cells is not usually influenced by corticosteroid treatment; however, the function of the T-cells, shown by the spectrum of cytokines produced, is clearly influenced. The cells that are most dramatically affected by local corticosteroid treatment are the Langerhans’cells, which completely disappear during treatment. This decrease suggests that there is a reduction in antigen presentation. The subsequent decrease in T-cell stimulation may result in a reduction of the reactions that are dependent on T-cell-derived mediators.

Notes: Topical corticosteroids have proved to be effective in the treatment of allergic rhinitis. The symptomatology of allergic rhinitis is considered to be the result of the accumulation and activation of inflammatory cells and cytokine release and hence the efficacy of corticosteroids is associated with their anti-inflammatory action. New advances in allergic inflammation now suggest that not only mast cells and eosinophils but also T-lymphocytes and antigen-presenting dendritic cells, play an important role in the inflammatory reaction. The effect of topical fluticasone propionate on cellular infiltration in the nasal mucosa is examined, with an emphasis on two studies performed in Rotterdam, The Netherlands. The cells influenced most by corticosteroid therapy were Langerhans' cells (antigen-presenting cells), which were almost completely eradicated, possibly resulting in diminished antigen presentation, and eosinophils. There was a reduction in the number of epithelial mast cells, but the number of T-lymphocytes only decreased following high doses of corticosteroid therapy or long-term treatment. However, T-lymphocyte function was influenced, as shown by the reduction in the T-helper, (ThJ-related cytokines, interleukin (1L)-4 and IL-5. Topical corticosteroid therapy had no effect on the accumulation of macrophages. The reduction in antigen presentation, and the decrease in T-lymphocyte stimulation and cytokine production, may cause a reduced influx of eosinophils and other inflammatory cells, resulting in diminished symptomatology.

Notes: Objective To investigate coagulation inhibitors and abnormalities of the homocysteine metabolism, which are related to an increased thrombotic risk, as risk factors for placental vasculopathy.Design A case-control study comparing nonpregnant women with an obstetric history of placental vasculopathy (study group) with nonpregnant women (control group) matched for age and occupation.Setting Obstetric outpatient clinic in the University Hospital Nijmegen.Sample One hundred and one women in the study group and 92 women in a control group.Methods Determinations in blood samples of homocysteine concentrations; the occurrence of 677 C→T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene; protein C activities; activated protein C resistance ratios; concentrations of free protein S antigen; antithrombin III activities; and the occurrence of factor V Leiden mutation.Results Increased risk for placental vasculopathy was found in the study group with elevated homocysteine (odds ratio 2.28, 95% CI 1.18–4.39), MTHFR mutation (odds ratio 3.29, 95% CI 1.03–10.5), decreased activated protein C resistance ratio (odds ratio 2.46, 95% CI 1.06–5.72) and protein C (odds ratio 2.01, 95% CI 1.11–3.65). Any combination of two risk factors in the same individual resulted in a 3.40 (95% CI 1.80–6.42) higher relative risk for placental vasculopathy; combinations of three risk factors in a 6.83 (95% CI 1.52–30.7) higher risk.Conclusions The thrombotic risk factors decreased levels of activated protein C resistance ratios and protein C, elevated homocysteine and the MTHFR 677 C→T mutation are likely risk factors for placental vasculopathy. Combinations of these risk factors in one individual resulted in synergistic increase of risk.

Notes: Phaeochromocytoma can mimic many serious disease entities. This report describes a 43-year-old man who presented with pulmonary oedema due to a phaeochromocytoma. Predominantly adrenaline-secreting tumours seem to predispose to this complication. Labetalol, a combined alpha- and beta-receptor blocker, should be considered as the initial treatment in these cases and continued during surgery.

Notes: The resistance of RAE, Rüsch, Mallinckrodt paediatric and Portex plain nasal and oral tracheal tubes with internal diameters 3.0 mm and 3.5 mm was calculated at air flows of 1 to 10 litres per minute. The flow resistance profiles of RAE and Rusch tracheal tubes was generally higher than those of Mallinckrodt paediatric and Portex plain tubes. All RAE and Rüsch nasotracheal tubes of size 3.0 mm internal diameter and orotracheal tubes 3.0 mm internal diameter had a flow resistance exceeding 3.0 kPa litres/second at an airflow of 4 litres/minute. It is concluded that these tracheal tubes ought only to be used with assisted or controlled ventilation.

Notes: Background Several authors described capsaicin, the pungent substance in red pepper, as an efficacious therapy for non-allergic non-infectious perennial rhinitis (NANIPER). Repeated capsaicin application induces peptide depletion and specific degeneration of the unmyelinated sensory C-fibres in the nasal mucosa.Methods We performed a placebo-controlled (NaCl 0.9%) study with 25 NANIPER patients. Daily record charts and visual analogue scales (VAS) were used for clinical evaluation. Nasal lavages were obtained before, during, and after treatment.Results There was a significant and long-term reduction in the VAS scores in the capsaicin group. No significant difference was found between the placebo and capsaicin treated groups for the mean group concentrations of leukotriene (LT) C4/D4/E4, prostaglandin D2 (PGD2). and tryptase. The levels of mast cell mediators, tryptase and PGD2. and leukotrienes, mediators derived from a variety of inflammatory cells, were low at baseline and comparable with levels observed in nasal lavages obtained from normals.Conclusion As involvement of inflammation could not be demonstrated, it is not surprising that capsaicin has no effect on inflammatory mediators. This suggests that inflammatory cells do not play a major part in the pathogenesis of NANIPER.

Notes: Mast cell degranulation is thought to be an important component of the pathogenesis of allergic rhinitis. Quantitative studies on mast cells in nasal mucosa after allergen exposure have given widely divergent results, ranging from an overall decrease via redistribution to an overall increase. We investigated this problem by employing a combination of anti-IgE and toluidine blue staining of biopsy specimens. In allergic patients anti-IgE was found to identify all mast cells and toluidine blue to detect mast cells that were not (totally) degranulated.The study was composed of two parts done in different patient groups. In the first part of the study biopsies were performed in 23 patients with isolated grass-pollen allergy, once during natural provocation in the summer and once in the winter. Biopsies were also performed in 12 controls. Non-allergic controls were found to have the same number of mast cells in the lamina propria as asymptomatic allergic patients. The controls seldom have mast cells in the epithelium. The patients with isolated grass-pollen allergy showed an increase in the numbers of mast cells in the lamina propria during natural provocation and the same seemed to occur in the epithelium as well. During natural provocation almost all of the mast cells in the epithelium and half of those in the lamina propria were degranulated.In the second part of the study 17 patients with isolated grass-pollen allergy and four controls were challenged daily with allergen extract during a 2-week period in the winter. During this period biopsies were performed at eight different occasions, i.e. once before, six occasions during and once after the provocation period. The results of this part of the study showed that during provocation mast cells migrate to the surface of the nasal mucosa, where they become degranulated, and that the pool of mast cells in the lamina propria was apparently replenished by migration of mast cells from the vessels in the lamina propria. The total number of mast cells in the lamina propria remained approximately the same while the mast cells residing in an increasingly thick layer measured from the basal membrane into the lamina propria became degranulated. After 2 weeks, 82% of the mast cells in the lamina propria was degranulated and it was only in the deepest layers that some toluidine blue positive cells were found.This study can explain the seemingly conflicting reports in the literature on mast cell dynamics and degranulation and shows that the reported differences are due to differences in the techniques used and the time of evaluation.

Notes: In a recent placebo-controlled study we demonstrated that capsaicin is an efficacious substance in the treatment of non-allergic non-infectious rhinitis. In this study the therapeutic effect lasted more than 9 months. This effect was not based on modulation of inflammation.To evaluate the effect of repeated application of capsaicin to patients with a nasal allergy to house dust mites (HDM), using the same treatment protocol as recently introduced in the treatment of non-allergic patients.Twenty-six patients with rhinitis, 15 females and 11 males (range: 20–46 years; mean 30.5), allergic to HDM were treated with either capsaicin or placebo in a double-blind, placebo-controlled, parallel group design. Nasal reactivity to HDM expressed as nasal symptoms, albumin and leukotriene levels in nasal lavage fluid and responsiveness to histamine, assessed as symptoms before and 6 weeks after treatment, were used to compare both treatment groups. In addition, visual analogue scales and rhinitis quality of life (RQL) assessment before, 6 weeks after and 3 months after treatment were used as outcome variables.No significant effect of capsaicin on nasal challenge tests with HDM (nasal symptoms, albumin and leukotriene levels), on VAS or RQL outcome 6 weeks or 3 month's after treatment, was demonstrated. Capsaicin did have a small effect on the area of the curve (AUC) of histamine dose response curves (P = 0.03).Desensitization with capsaicin in doses sufficient to control symptoms in patients with severe non-allergic rhinitis is lacking therapeutic effect in perennial allergic rhinitis.