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Notes: The superconducting super collider rf-driven volume ion source routinely provided 35 kV, (approximately-greater-than)30 mA H− beams with normalized rms emittances (cursive-epsilonn-rms) 〈0.1 π mm mrad. The source was typically operated with a 100 μs beam pulse width at a 10 Hz repetition rate. To enhance H− output, the ion source was modified to accommodate a set of cesium dispensers so that a trace amount of cesium could be introduced into the plasma grid collar. A plasma grid heater element controls the temperature of the cesiated surfaces and the rate of cesium dispensation. Beam currents in excess of 100 mA and electron to H− current ratios close to one have been observed. Emittance measurements at 70 mA suggest a 20% increase over uncesiated emittance values. Improvements in the beam emittance are fully expected when the extraction optics are optimized. This enhanced, very reliable source is a strong candidate for high current H− accelerators. © 1995 American Institute of Physics.

Notes: The Superconducting Super Collider (SSC) ion source is required to provide a 30 mA H− beam at 35 keV with a normalized rms emittance (εn-rms) of less than 0.18 π mm mrad. An rf-driven volume source was chosen for the commissioning of the SSC linear accelerator (Linac). The divergent ion source output beam is matched into the radio frequency quadrupole accelerator (RFQ) by an electrostatic low-energy beam transport (LEBT). The SSC Linac injector (consisting of ion source, LEBT, and RFQ) is required to provide 25 mA of H− beam (pulse width of 9.6–35 μs at 10 Hz repetition rate) at 2.5 MeV with transverse normalized rms emittance (εt-n-rms) of less than 0.2 π mm mrad and longitudinal normalized rms emittance (εl) of less than 0.82×10−6 eV s. The performance of our rf volume source and initial experimental results from the SSC injector are discussed.

Notes: To evaluate the performance of a high current H− rf-driven volume ion source, the Superconducting Super Collider ion source was modified to accommodate a set of cesium dispensers so that a trace amount of cesium could be introduced into the plasma grid collar. A plasma grid heater element controls the temperature of the cesiated surfaces and the rate of cesium dispensation. With this modification, beam currents in excess of 100 mA and electron to H− current ratios close to one have been observed. In contrast, the uncesiated source provided 30 mA of H− beam with an e/H− ratio ≥25. In both cases the source was operated with a 100 μs beam pulse width at a 10 Hz repetition rate, and an extraction voltage of 35 kV. This cesium enhanced source is a strong candidate for use in high current H− accelerators. © 1996 American Institute of Physics.

Notes: Background Enhanced skin mast cell releasability of histamine, increased production of histamine releasing factor (HRF), and cutaneous inflammatory process are the hallmarks of chronic idiopathic urticaria (CU). Although H1-antihistamines are known to alleviate the symptoms effectively in most cases, systemic corticosteroids (CS) are given in more resistant patients. Their mode of action remains a matter of controversy.Objectives In the present study, the effects of a 7-day course of CS or placebo on histamine content and HRF production iti non-lesional skin of 19 CU patients were examined.Methods Using the skin chamber technique, HRF production and histamine content were assessed in normal-appearing skin of patients with CU over a 2-h observation period. Those two parameters were measured before and after treatment, in a double-blind fashion.Results No significant changes occurred in any parameters after placebo treatment. In contrast with this, significant decrease of HRF activity was observed after 1 week of oral methylprednisolone while no change was documented for histamine secretion. Conclusion These data suggest that CS therapy improves symptoms of CU in association with a decreased production of HRF in uninvolved skin.

Notes: Background and objectives The determinants of variability in the clinical expression of atopy are still to be documented. The goals of this study were to determine, in subjects with a clinical diagnosis of symptomatic asthma or rhinitis, what is the possible contribution of different types of indoor and outdoor allergens to the development of their disease, by looking at the prevalence and degree of sensitization to these allergens according to age and gender.Subjects and methods We analysed allergy skin prick tests to common airborne indoor and outdoor allergens in 3371 consecutive patients, grouped according to diagnosis of allergic asthma, rhinitis, or both. For each of these three groups, we calculated the prevalence of sensitization to indoor/outdoor allergens, the atopic index (Al), the number of positive responses to allergy skin prick test and the mean wheal diameter (MWD) of these responses.Results The prevalence of atopy and the values of Al and MWD peaked in subjects aged 16 to 25 years, declining afterwards; in subjects ± 18 years old, atopic indices were slightly higher in men than in women. In atopic subjects, the prevalence of sensitization was, in decreasing order: housedust (84.2%), cat hair-epithelium (76.5%), dog hair-dander (63.0%), house dust mite (54.2%), grasses (51.9%), trees (47.2%) and ragweed pollens (44.9%) and finally, moulds (25.4%). Among subjects sensitized only to outdoor allergens (n= 195), 73.8% had a rhinitis, 11.8% had asthma and 14.4% had both diagnoses; for those sensitized only to indoor allergens (n= 710), these values were respeetively 48.6, 24.5 and 26.9%, and for those sensitized to both indoor and outdoor allergens (n= 1793), the comparable values were 55.5, 14.6 and 29.9%.Conclusion These data show that in our population of subjects with respiratory allergic symptoms, indoor allergen sensitization is strongly associated with asthma, while exclusive sensitization to pollens is associated primarily with rhinitis. Sensitization was more prevalent for indoor allergens than for outdoor allergens in all groups determined according to diagnosis or age. Indices of atopy were higher in men in the group ± 18 years old. Prevalence and degree of sensitization were shown to peak in young adults, regardless of the allergen, and to diminish with age. This study stresses the role of indoor allergens in the development of asthma and shows the variability of allergic manifestations according to the type of sensitization.

Notes: The reverse haemolytic plaque assay was developed to measure antigen (AgE or rye grass I)-specific IgE-plaque-forming cells from the peripheral-blood lymphocytes of ragweed- and grass-allergic patients. The anti-IgE-developing antisera was shown to be isotype-specific, and the response of the assay was inhibited by 52% by the addition of 10 pg of antigen. In addition, the assay was shown to have a reproducibility (s.d.) of 15%. The blood lymphocytes from all fifteen atopic (grass and ragweed) patients were shown to form antigen-specific IgE-plaque-forming cells during the pollen season (mean value 115 cells) and up to 6 months after the season (mean value 56 cells). Cycloheximide appears to block the formation of the plaque-forming cells. This method appears to be sensitive and reproducible enough to study in vitro IgE antibody synthesis of peripheral-blood lymphocytes from atopies.

Notes: Background Patients with severe asthma are often inadequately controlled on existing anti-asthma therapy, constituting an unmet clinical need.Objective This randomized, double-blind, placebo-controlled trial evaluated the ability of omalizumab, a humanized monoclonal anti-IgE antibody, to improve disease control sufficiently to enable inhaled corticosteroid reduction in patients with severe allergic asthma.Methods After a run-in period when an optimized fluticasone dose (〈inlineGraphic alt="geqslant R: gt-or-equal, slanted" extraInfo="nonStandardEntity" href="urn:x-wiley:09547894:CEA1916:ges" location="ges.gif"/〉1000 μg/day) was received for 4 weeks, patients were randomized to receive subcutaneous omalizumab [minimum 0.016 mg/kg/IgE (IU/mL) per 4 weeks; n=126] or matching placebo (n=120) at intervals of 2 or 4 weeks. The study comprised a 16-week add-on phase of treatment followed by a 16-week fluticasone-reduction phase. Short-/long-acting β2-agonists were allowed as needed.Results Median reductions in fluticasone dose were significantly greater with omalizumab than placebo: 60% vs. 50% (P=0.003). Some 73.8% and 50.8% of patients, respectively, achieved a 〈inlineGraphic alt="geqslant R: gt-or-equal, slanted" extraInfo="nonStandardEntity" href="urn:x-wiley:09547894:CEA1916:ges" location="ges.gif"/〉50% dose reduction (P=0.001). Fluticasone dose reduction to 〈inlineGraphic alt="leqslant R: less-than-or-eq, slant" extraInfo="nonStandardEntity" href="urn:x-wiley:09547894:CEA1916:les" location="les.gif"/〉500 μg/day occurred in 60.3% of omalizumab recipients vs. 45.8% of placebo-treated patients (P=0.026). Through both phases, omalizumab reduced rescue medication requirements, improved asthma symptoms and asthma-related quality of life compared to placebo.Conclusion Omalizumab treatment improves asthma control in severely allergic asthmatics, reducing inhaled corticosteroid requirements without worsening of symptom control or increase in rescue medication use.

Notes: The role of IL-4 on IgE synthesis has been well established. IL-4 has been shown to promote IgE production by B cells from atopic and non-atopic donors. In this study, the effects of natural exposure to pollens on IL-4-indueed IgE synthesis by peripheral blood mononuclear cells of atopic and non-atopic donors were examined. The results confirm production of IgE in an IL-4 dose-dependent manner by PBMC cultures of these two groups. When cultures were performed out of the pollen season, following stimulation by IL-4, no significant difference was observed between the levels of IgE produced by PBMC of atopic and non-atopic donors. In contrast, upon natural exposure to pollens, significant higher levels of IgE were measured in the atopic group than in the non-atopic one. These results show that the policn season infiuences the IL-4-induced IgE synthesis by PBMC of allergic patients and are in keeping with seasonal rise of specific IgE antibodies.

Notes: In the present study, it was shown that allergen challenge in vitro produced an increase in the number of antigen-specific IgE-plaque-forming cells of peripheral-blood lymphocytes from grass- or ragweed-allergic patients. Thus, the blood lymphocytes of all twelve (four rye grass I and eight AgE) sensitive donors responded whereas the blood lymphocytes of five non-atopic controls were unresponsive to antigen challenge. Allergen challenge doses of 10−10−10−12 g/ml were found to give the greatest number of plaque-forming cells whereas the number of plaque-forming cells at challenging doses between 10−9 and 10−7 g/ml were either the same or less than those obtained with unchallenged cells. The results are discussed as to whether this in vitro model system represents in vivo response to allergen of the allergic patient.