Clinical standardization of two controlled allergen challenge facilities: The Environmental Exposure Unit and the Biogenics Research Chamber.

BACKGROUND: Controlled allergen challenge facilities (CACF), in disparate geographic regions with dissimilar engineering and base populations, have historically functioned as single, independent sites in clinical allergy trials. We aimed to demonstrate "between-unit reproducibility" to allow controlled challenge trials of participants using 2 CACFs. OBJECTIVE: To compare and standardize 2 CACFs located in Kingston, Ontario, Canada, and San Antonio, Texas, by examining participant-reported symptom severity during qualifying and treatment visits and evaluating response to treatment, while using the same allergen. METHODS: At 2 different CACFs, participants were enrolled in a double-blind, placebo-controlled, crossover intervention trial with cetirizine 10 mg. Different distribution devices delivered common short ragweed pollen via laminar air flow and maintained an airborne concentration of 3500 ± 700 grains/m3 in both facilities. A 1-hour "sham" run with no pollen release preceded a priming exposure of 3 hours and was followed 3 days later by a qualifying/treatment 5-hour exposure. At least 14 days later, another priming exposure was followed by the crossover exposure and treatment. RESULTS: Forty-eight and 43 subjects completed the study at Kingston and San Antonio, respectively. Demographics were similar. Fewer than 10% exhibited symptoms with sham exposure. No significant differences were found between the 2 facilities in maximal total rhinoconjunctivitis symptom score, total nasal symptom score, and total ocular symptom score, nor in areas under the curve. In both facilities, no significant effects of cetirizine 10 mg over placebo were detected. CONCLUSION: The results were equivalent, demonstrating that the 2 CACFs can be used together in dual-center clinical trials and show the possibility of multicenter trials involving multiple CACFs.

[[Effect of erythropoietin and its combination with hypoxic altitude chamber training on the clinical and functional manifestations of chronic glomerulonephritis].

AIM: To evaluate the efficiency of treatment for renal anemia in patients with chronic glomerulonephritis (CGN), by using erythropoietin and its combination with hypoxic altitude chamber training (HACT). SUBJECTS AND METHODS: Sixty-three patients (41 men and 22 women) (mean age 37.1 ± 3.3 years) with CGN during the predialysis phase of chronic kidney disease (CKD) complicated by anemia. Hemoglobin (Hb), packed cell volume (PCV), and red blood cell indices (mean corpuscular volume (MCV) and mean corpuscular hemoglobin concentration (MCHC)), platelet count, serum iron, fibrinogen, C-reactive protein (CRP) and creatinine levels were determined in all the patients at baseline and during a prospective follow-up. Glomerular filtration rate (GFR) was measured using with the Rehberg-Tareev test. Along with standard renal protective therapy, all the patients received either epoetin beta (n=31; Group 1) or its combination with HACT (n=32; Group 2). In Group 1 patients (n=31), erythropoietin (EPO) was given in an initial dose of 20-50 IU/kg thrice daily, followed by the dose being adjusted until the target Hb level was reached. Group 2 patients (n=32) received HACT cycles by the standard procedure in combination with EPO given in lower doses (20-50 IU/kg once weekly). A prospective .follow-up of the patients was carried out during one year. RESULTS: Following one year, the number of patients who had achieved the target Hb level was 74.1% in Group 1 and 87.5% in Group 2. Over time, there were increases in the concentration of Hb (from 108.6 ± 19.4 to 124.5 ± 14.09 g/l; p<0.05), PCV, and red blood cell indices (MCV, MCHC) in the patients receiving EPO (Group 1). Besides an'anti-anemic effect, there was a significant decrease in the concentrations of fibrinogen from 6655 (4884-7634) to 3776 (3330-4884) mg/dL; (p<0.05), serum creatinine from 159 (89--261) to 138 (79-258) pmol/I (p<0,05), proteinuria from 2.955 (1.024-6.745) to 2.069 (0.539-4.279) (p<0.05), which was accompanied by an increase in GFR from 62.3 (37.0 - 107.4) to 76.9 (46.0-96.0) mi/min (p<0.05). In Group 2, the rise in the concentration of Hb (from 114.1 ± 11.7 to 132.0 ± 16.5 g/I (p<0.05), PCV, MCV, and MCHC proved to be more pronounced than that in Group 1 (p<0.05) and accompanied by an elevation in the counts of platelets (from 222.7 ± 19.8.10(9)/1 to 249.3 ± 21.9.10(9)/1 (p<0:05)) and red blood cells (from 4.0 ± 0.4-10(12)/1 to 4.34 ± 0.3 X 10(12)/I (p<0.05)). There was a more marked reduction in the degree of proteinuria from 3.092 (0.764-7.694) g at baseline to 1.600 (0.677-4.078) g one year later (p<0.05) than that in Group 1 (p<0.05). The increase in GFR from 60.1 (46.0-96.0) to 79.4 (44.0-120.0) ml/min (p<0.05) and the fall in the concentration of fibrinogen from 5555 (4884-7770) to 4107 (3776-5328) mg/dL (p<0.05) and serum creatinine from 166 (92-273) to 147 (92-152) µmol/L (p<0.05), which were observed in Group 2, were comparable to those in Group 1. CONCLUSION: Epoetin beta used in patients with CGN has an anti-anemic effect and leads to improved renal nitrogen-excretory function. Erythropoietin in combination with HACT used in CGN provides a higher anti-anemic efficacy and a more pronounced antiproteinuric effect.

Pranlukast dry syrup inhibits symptoms of Japanese cedar pollinosis in children using OHIO Chamber.

Pranlukast (PLK) is a leukotriene receptor antagonist (LTRA) that has been approved for treatment of asthma in patients of all ages and allergic rhinitis (AR) in adults but not for AR in children in Japan. This randomized, double-blind, placebo-controlled, crossover study used an artificial exposure chamber (OHIO Chamber) to investigate the efficacy and safety of PLK in children from 10 to 15 years old with seasonal AR (SAR) due to Japanese cedar (JC) pollen. Eighty-four subjects were enrolled and randomized to the treatment arm and 74 were included in the per protocol set. Subjects received either PLK dry syrup (DS) or placebo for 1 week. They were challenged with JC pollen in the OHIO Chamber for 3 hours. Total nasal symptom scores (TNSSs) were recorded every 30 minutes during the exposure. PLK DS treatment suppressed the TNSS changes from baseline significantly when compared with placebo. The difference in the least square means in TNSS between the PLK DS-treated group and placebo group was -0.37 (95% CI, -0.54, -0.20) with a value of p < 0.0001, showing that PLK DS significantly suppressed the nasal symptoms. Regarding specific nasal symptoms, PLK DS significantly suppressed sneezing, nasal discharge, and nasal obstruction. The effect of PLK DS on nasal obstruction was most prominent, with significant improvement relative to placebo beginning 60 minutes after the start of exposure. No serious adverse events were reported during the study. In this study, PLK DS is effective and safe for treatment in children with SAR.

Full-scale chamber investigation and simulation of air freshener emissions in the presence of ozone.

Volatile organic compound (VOC) emissions from one electrical plug-in type of pine-scented air freshener and their reactions with O3 were investigated in the U.S. Environmental Protection Agency indoor air research large chamber facility. Ozone was generated from a device marketed as an ozone generator air cleaner. Ozone and oxides of nitrogen concentrations and chamber conditions such as temperature, relative humidity, pressure, and air exchange rate were controlled and/or monitored. VOC emissions and some of the reaction products were identified and quantified. Source emission models were developed to predict the time/concentration profiles of the major VOCs (limonene, alpha-pinene, beta-pinene, 3-carene, camphene, benzyl propionate, benzyl alcohol, bornyl acetate, isobornyl acetate, and benzaldehyde) emitted bythe air freshener. Gas-phase reactions of VOCs from the air freshener with O3 were simulated by a photochemical kinetics simulation system using VOC reaction mechanisms and rate constants adopted from the literature. The concentration-time predictions were in good agreement with the data for O3 and VOCs emitted from the air freshener and with some of the primary reaction products. Systematic differences between the predictions and the experimental results were found for some species. Poor understanding of secondary reactions and heterogeneous chemistry in the chamber is the likely cause of these differences. The method has the potential to provide data to predict the impact of O3/VOC interactions on indoor air quality.

Automated feedback control of an inhalation exposure system with discrete sampling intervals: testing, performance, and modeling.

The application of a proportional-integral-derivative (PID) control algorithm to an inhalation exposure system using a building automation system is described. Previous studies had utilized a control system in which concentration was monitored continuously and adjustments to the generator were made on a continuous basis. In this system, benzene vapor was generated into a chamber, and a gas chromatograph was used to measure the concentration in a chamber at discrete 30-min intervals. Thus only limited opportunities were available to sample and adjust the vapor generator flow rate. A series of tests were conducted in which the generator was operated without control, with control, with an additional load, and with nonoptimal settings. The results showed that the PID control loop could function effectively to restore a system back to the target set point, even with an additional load on the system. With nonoptimal control settings, the system showed oscillatory behavior. A model to simulate operation of the chamber was developed on a spreadsheet program. The model was accurate at simulating the various testing scenarios and useful for selecting the proper control settings. A PID feedback control system operating with a concentration monitoring system that sampled on a 30-min cycle was shown to produce exposures that were accurate in matching the target set point and maintaining a constant concentration.

Relation of pulmonary responses induced by 6.6-h exposures to 0.08 ppm ozone and 2-h exposures to 0.30 ppm ozone via chamber and face-mask inhalation.

While direct comparison of pulmonary responses to 6.6-h exposures to 0.08 to 0.12 ppm ozone O3 have demonstrated that chamber and face-mask inhalation methods yield closely similar results, no comparative study of responses to 2-h intermittent exercise (IE) exposures to higher O3 concentrations have been reported. The present study was designed to achieve three primary objectives: (1) to compare pulmonary function and symptoms effects of a 2-h IE exposure to 0.30 ppm O3 via chamber and via face mask; (2) to compare the pulmonary effects of 6.6-h chamber exposure to 0.08 ppm O3 to those observed in 2-h IE 0.30 ppm O3 exposures via chamber and via face mask; and (3) to examine filtered air (FA) recovery pulmonary and symptoms responses following chamber exposures of 6.6 h to 0.08 ppm O3 and 2 h to 0.30 ppm O3. A simple regression of postexposure percent change in FEV(1.0) for the 2-h IE, 0.30-ppm O3 chamber exposure as a function of postexposure percent change in FEV(1.0) for the 2-h IE, 0.30-ppm O3 exposure with face mask yielded an R(2) of 0.83. Further, a regression of the postexposure FEV(1.0) response to the chamber 6.6-h, 0.08-ppm O3 exposure as a function of postexposure FEV(1.0) response to the face mask 2-h IE, 0.30-ppm O3 exposure (R(2) of 0.34) was similar to the 0.40 value obtained for the two chamber exposures FEV(1.0) response comparison. Results of the 1.4-h FA recovery following the two chamber O3 exposures showed different rates of FEV(1.0) and symptoms rectification that appeared related to the total O3 dose (product of O3 concentration, ventilation rate, and duration). More data are needed to clarify short-term recovery of O3-induced pulmonary effects and how they may be related to the more abundant data available on the delayed recovery of pulmonary function seen over longer time periods, such as 24 h.

[Technology of hyperbaric chambers]. / Kammertechnik.

Technical requirements for hyperbaric chambers are subject to permanent change. Medical gas supplies, the chamber hulls, control systems, medical equipment as well as the security check-up modalities have been constantly adapted according to the most recent technical developments. Moreover, different subtypes of hyperbaric chambers such as treatment facilities, chambers used for training purposes or facilities set up for primary experimental use require specific technical outfit. Keeping in mind some recent tragic accidents in hyperbaric facilities, chamber security is of foremost importance. Alarm- as well as technical monitoring systems, fire-fighting equipment, deluge systems and pressure locks are absolute requirements for any hyperbaric chamber. In chambers used for therapeutic purposes the possibility of invasive and noninvasive patient monitoring as well as hygienic standards have to be ensured.

A computerized databank of decompression sickness incidence in altitude chambers.

This report describes a hypobaric decompression sickness databank (HDSD) for use with personal computers. The databank consolidates some of the decompression sickness (DCS) information that has accumulated from altitude chamber tests from 1942 to the present. The information was transcribed to a data collection form, screened for accuracy and duplication, and then added to the databank through a computer keyboard. The databank consists of two files; 63 fields contain details of the test conditions in the altitude chamber, the outcome of the test in terms of DCS and venous gas emboli, the physical characteristics of the group of subjects who underwent the test, and the denitrogenation procedures prior to decompression. The HDSD currently contains 378 records that represent 130,012 altitude exposures from 80 sources: scientific journal articles, government and contractor reports, and chapters from books.