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K Richter

Publications and source records attributed to K Richter.

At least 19 recordsLinked to original sources
PubMed2006

Randomised trial comparing as-needed versus regular treatment with formoterol in patients with persistent asthma.

PURPOSE: The aim of this study was to demonstrate the equivalent efficacy of inhaled formoterol in asthmatic patients, either given as-needed or on a regular twice-daily schedule. METHODS: Randomised, open 12-week study in patients with mild to moderate asthma not adequately controlled with inhaled glucocorticosteroids alone. Patients received inhaled formoterol as needed or on a regular schedule (2x2 puffs/day with 6 microg formoterol per puff). Patients in the twice-daily formoterol group could use salbutamol as a rescue medication. The primary endpoint was the number of patients with asthma exacerbations in each group. RESULTS: Thirty-nine centres randomised 359 patients. The number of patients with asthma exacerbations showed neither a clinically relevant nor a statistically significant difference between groups: formoterol as-needed: 3.95% (7 of 177); twice daily: 3.45% (6 of 174). Patients in the formoterol as-needed group used significantly less formoterol (-1.5 puffs per day; P<0.0001). Including the saved rescue medication (up to one puff per day), total beta-2 agonist use in the formoterol as-needed group decreased by approximately 2-2.5 puffs per day. Both formoterol treatment schedules were well tolerated. Musculoskeletal pain and tremor were less frequent in the formoterol as-needed group: headaches were slightly more frequent. CONCLUSION: Formoterol given as needed and without additional beta-2 agonist, and formoterol given on a regular basis twice daily, supplemented by salbutamol as a rescue medication, appeared equally effective in this clinical study. Drug consumption was markedly lower in the former group.

Administration, Inhalation↗
PubMed2006

Spermidine synthase is prominently expressed in the striatal patch compartment and in putative interneurones of the matrix compartment.

The ubiquitous polyamines spermidine and spermine are known as modulators of glutamate receptors and inwardly rectifying potassium channels. They are synthesized by a set of specific enzymes in which spermidine synthase is the rate-limiting step catalysing the formation of the spermine precursor spermidine from putrescine. Spermidine and spermine were previously localized to astrocytes, probably reflecting storage rather than synthesis in these cells. In order to identify the cellular origin of spermidine and spermine synthesis in the brain, antibodies were raised against recombinant mouse spermidine synthase. As expected, strong spermidine synthase-like immunoreactivity was obtained in regions known to express high levels of spermidine and spermine, such as the hypothalamic paraventricular and supraoptic nuclei. In the striatum, spermidine synthase was found in neurones and the neuropil of the patch compartment (striosome) as defined by expression of the micro opiate receptor. The distinct expression pattern of spermidine synthase, however, only partially overlapped with the distribution of the products spermidine and spermine in the striatum. In addition, spermidine synthase-like immunoreactivity was seen in patch compartment-apposed putative interneurones. These spermidine synthase-positive neurones did not express any marker characteristic of the major striatal interneurone classes. The neuropil labelling in the patch compartment and in adjacent putative interneurones may indicate a role for polyamines in intercompartmental signalling in the striatum.

Animals↗
PubMed2006

[Hyperuricemia and gout: diagnosis and therapy].

In our modern society hyperuricemia is one of the most frequent metabolism disturbances. So far, every fourth man and every tenth woman suffer from an asymptomatic or a symptomatic hyperuricemia named gout. Mostly, over nutrition and malnutrition as well as other secondary factors with a genetically determined renal secretion disturbance of uric acid lead to an increase of serum uric acid. By deposition of uric acid crystals in tissues with intermittent immunologic activation of inflammation cells a manifestation of gout can be seen. The clinical image of gout varies widely. It may manifest as acute or chronic arthritis, tophi on the skin, subcutaneous tissue and the skeletal system as well as urate nephropathy. To eliminate the consequences of hyperuricemia in the long term, apart from a thorough anamnesis of nutritional habits a general examination of metabolic parameters is necessary to exclude a metabolic syndrome and other causes for a secondarily caused hyperuricemia. As gout is very often primarily caused by a renal secretion disturbance of uric acid special diagnostics should be done. Basing on literature research and inclusion of experts opinions this article represents the therapeutically options in treatment of hyperuricemia and gout with their resulting side effects and contraindications.

Allopurinol↗
PubMed2006

Relative quantitation of protein-protein interaction strength within the yeast two-hybrid system via fluorescence beta-galactosidase activity detection in a high-throughput and low-cost manner.

The yeast two-hybrid (Y2H) method is capable of delivering vast amounts of interacting positive yeast colonies from a single library screen, particularly if a multifunctional protein is used as bait. However, the selection of definitive colonies for further molecular analysis is limited by both technical practicality and high costs. Here we demonstrate a cost-effective and simple method for the rapid selection and ranking of those Y2H-positive interaction clones that are suitable for further analysis. We performed a Y2H screen for the identification of human transforming growth factor beta2- interacting proteins in a human skin keratinocyte library. The identified clones were ranked by the amount of beta-galactosidase enzyme produced, as well as by the interaction strength of the positive colonies. The combination of high-throughput microplate fluorescence readers and specific fluorescence assays can be utilized for relative quantitation of protein-protein interaction strength of Y2H-positive colonies in crude yeast-cell lysates. We demonstrate here that the high sensitivity of the fluorescence approach can bypass cumbersome conventional methods of cell lysis used in beta-galactosidase assays, and still deliver accurate values for analysis of protein interaction data. Finally, we also achieved a better understanding of general aspects of beta-galactosidase measurements in the Y2H system, such as protein normalization, the influence of yeast culture incubation time on optimal beta-galactosidase detection, and the linearity of beta-galactosidase detection in crude cell lysates.

Cost-Benefit Analysis↗
PubMed2006

Alternaria alternata NADP-dependent mannitol dehydrogenase is an important fungal allergen.

BACKGROUND: Alternaria alternata is one of the most important allergenic fungi worldwide. Mannitol dehydrogenase (MtDH) has previously been shown to be a major allergen of Cladosporium herbarum and cross-reactivity has been demonstrated for several fungal allergens. OBJECTIVE: The present study's objective was to clone the MtDH from an A. alternata cDNA library, express and purify the recombinant non-fusion protein and test its IgE-binding properties. Methods A cDNA library prepared from A. alternata hyphae and spores was screened for mannitol dehydrogenase by DNA hybridization with the radioactively labelled C. herbarum homologue as a probe. The resulting clone was sequenced and heterologously expressed in Escherichia coli as a recombinant non-fusion protein, which was purified to homogeneity and analysed for its IgE-binding capacity. RESULTS: The coding sequence of the full-length cDNA clone comprises 798 bp encoding a protein with a molecular mass of 28.6 kDa and a predicted pI of 5.88. Protein sequence analysis revealed an identity of 75% and a homology of 86% between the MtDHs of A. alternata and C. herbarum. The functional mannitol dehydrogenase was expressed in the E. coli strain BL21(DE3) transformed with the vector pMW172 and purified to homogeneity. The enzyme catalyses the NADPH-dependent conversion of d-fructose to d-mannitol. In IgE-ELISA and immunoblots, MtDH is recognized by 41% of A. alternata-allergic patients. In vivo immunoreactivity of the recombinant MtDH was verified by skin prick testing. Finally, inhibition-ELISA experiments confirmed cross-reactivity between the MtDHs of A. alternata and C. herbarum. CONCLUSION: Mannitol dehydrogenase (Alt a 8) represents an important new allergen of the ascomycete A. alternata that might be suitable for improving diagnostic and therapeutic procedures.

Allergens↗
PubMed2006

Controlled trial of multidisciplinary care teams for acutely ill medical inpatients: enhanced multidisciplinary care.

BACKGROUND: Acute hospital general medicine services care for ageing complex patients, using the skills of a range of health-care providers. Evidence suggests that comprehensive early assessment and discharge planning may improve efficiency and outcomes of care in older medical patients. AIM: To enhance assessment, communication, care and discharge planning by restructuring consistent, patient-centred multidisciplinary teams in a general medicine service. METHODS: Prospective controlled trial enrolling 1538 consecutive medical inpatients. Intervention units with additional allied health staff formed consistent multidisciplinary teams aligned with inpatient admitting units rather than wards; implemented improved communication processes for early information collection and sharing between disciplines; and specified shared explicit discharge goals. Control units continued traditional, referral-based multidisciplinary models with existing staffing levels. RESULTS: Access to allied health services was significantly enhanced. There was a trend to reduced index length of stay in the intervention units (7.3 days vs 7.8 days in control units, P = 0.18), with no change in 6-month readmissions. In-hospital mortality was reduced from 6.4 to 3.9% (P = 0.03); less patients experienced functional decline in hospital (P = 0.04) and patients' ratings of health status improved (P = 0.02). Additional staffing costs were balanced by potential bed-day savings. CONCLUSION: This model of enhanced multidisciplinary inpatient care has provided sustainable efficiency gains for the hospital and improved patient outcomes.

Acute Disease↗
PubMed2005

The role of moisture in the nest thermoregulation of social wasps.

Paper nests of social wasps are intriguing constructions for both, biologists and engineers. We demonstrate that moisture and latent heat significantly influence the thermal performance of the nest construction. Two colonies of the hornet Vespa crabro were investigated in order to clarify the relation of the temperature and the moisture regime inside the nest. Next to fairly stable nest temperatures the hornets maintain a high relative humidity inside the nest. We found that in consequence a partial vapor-pressure gradient between nest and ambient drives a constant vapor flux through the envelope. The vapor flux is limited by the diffusion resistance of the envelope. The driving force of vapor flux is heat, which is consumed through evaporation inside the nest. The colony has to compensate this loss with metabolic heat production in order to maintain a stable nest temperature. However, humidity fluctuations inside the nest induce circadian adsorption and desorption cycles, which stabilize the nest temperature and thus contribute significantly to temperature homeostasis. Our study demonstrates that both mechanisms influence nest thermoregulation and need to be considered to understand the thermodynamic behavior of nests of wasps and social insects in general.

Animals↗
PubMed2005

Effect of propiverine on cytochrome P450 enzymes: a cocktail interaction study in healthy volunteers.

The present study was conducted to assess a possible in vivo effect of propiverine, an anticholinergic drug to treat urinary incontinence and related disorders, on the activity of intestinal CYP3A4 and of hepatic CYP3A4, CYP2C9, CYP2C19, and CYP1A2. The activity of the respective cytochromes P450 was measured using the following metrics of selective substrates given as a tailored low-dose phenotyping cocktail: intestinal availability of midazolam (2 mg orally), clearance of midazolam (1 mg i.v.), apparent clearance of tolbutamide (125 mg orally), urinary excretion of 4'-hydroxymephenytoin 0 to 8 h postdose (50 mg of mephenytoin orally), and the paraxanthine/caffeine plasma ratio 6 h postdose (150 mg of caffeine orally). These metrics were determined in 16 healthy young men at the end of 7 days of treatment with 15 mg of propiverine (test) or placebo (reference) twice daily. All phenotyping drugs were quantified by liquid chromatography-tandem mass spectrometry. Chronic propiverine treatment reduced hepatic and intestinal CYP3A4 activity slightly to 0.89-fold and 0.80-fold, respectively [90% confidence interval (CI) for test/reference ratios 0.85-0.93 and 0.72-0.89], with the combined effect resulting in a 1.46-fold increase in area under the curve of oral midazolam (90% CI 1.36-1.57). Propiverine had no relevant effect on CYP2C9, CYP2C19, and CYP1A2 (90% CI for test/reference ratios 0.93-1.00, 0.84-0.96, and 0.97-1.07, respectively). All study drugs were well tolerated. In conclusion, propiverine has a minor potential to cause drug-drug interactions.

Adult↗
PubMed2005

[Extravasal position of central venous catheters despite unsuspicious ECG-guidance].

OBJECTIVE: Does the electrocardiographic method for central venous catheter positioning distinguish between a correct intravasal and a malpositioned extravasal position? METHODS: 24 cardiac surgical patients were enrolled in this prospective observational study. In 18 patients the left, in another 6 patients the right internal jugular vein was cannulated. Using a J-wire within a triple-lumen catheter the amplitude of the P-wave was measured at 3 different intravasal sites: Intra-1: (intravasal baseline electrocardiogram), i. e. 10 cm marking of the catheter on skin level; Intra-2: clear rise of the P-wave amplitude upon further insertion of the catheter; Intra-3: maximum P-wave amplitude. At this position the control of the catheter tip was achieved by means of transoesophageal echocardiography (TOE). Intraoperatively, another J-wire within a triple-lumen catheter was placed by the heart surgeon on 3 extravasal sites and the ECG was recorded: Extra-1: extravasal at the left innominate vein above the pericardial reflection; Extra-2: extravasal on the superior vena cava below the pericardial reflection; Extra-A: extravasal on ascending aorta below the pericardial reflection. The catheter was suture fixed with its tip in position Intra-3. Post surgery a chest radiograph was taken. RESULTS: All catheter tips were visualised at the basis of the Crista terminals (border between right atrium and superior vena cava) by TOE control. The rise of the P wave amplitude at Intra-2, Extra-2 and Extra-A was highly significant compared to the base line at Intra-1 (Intra-1/Intra-2, Intra-1/Extra-2, Intra-1/Extra-A: p in each case < 0.001). The P wave amplitudes of the corresponding intra- and extravasal positions of the left innominate vein (Intra-1/Extra-1, n = 18, p = 0.096)) as well as those of the superior vena cava (Intra-2/Extra-2, n = 24, p = 0.859) did not differ. CONCLUSION: The electrocardiographic method can not differentiate between intra- and extravasal position of a central venous catheter, and thus, presumably fails to identify malpositioning as a result of vascular perforation.

Aged↗
PubMed2004

Kidney function in mice: thiobutabarbital versus alpha-chloralose anesthesia.

Mice that lack or over-express a gene of interest are important tools for unraveling gene function. The determination of single nephron function by micropuncture or precise determination of glomerular filtration rate (GFR) by inulin clearance method require experiments under anesthesia. A good anesthetic protocol should allow for reasonable and stable glomerular and tubular function. The aim of this study was to compare the commonly used thiobutabarbital (TBB) versus alpha-chloralose (CHL) anesthesia with regard to absolute levels and the stability of blood pressure, heart rate, and kidney function. Male CD1 mice were anesthetized with TBB (100 mg/kg body weight i.p.) or CHL (120 mg/kg body weight i.p.), plus ketamine (100 mg/kg body weight i.m.) given to every mouse for analgesia. After preparation for clearance experiments, two 30-min urine collections were performed at periods 1 and 2 (P1 and P2). It was observed that heart rate and mean arterial blood pressure did not differ between TBB ( n=9) vs. CHL ( n=9) and were stable through P1 and P2. In CHL, GFR as well as fractional excretion of fluid, Na(+) and K(+) were stable from P1 to P2 (P1: 190+/-15 microl/min, 1.6+/-0.2%, 0.7+/-0.1%, 35+/-5%; percent change in P2: 1+/-6, 26+/-10, 29+/-15, 6+/-10 respectively). In TBB, GFR was significantly greater vs. CHL in P1 and did not significantly change in P2 (246+/-8 microl/min, p<0.05; percent change: -6.5+/-4). Fractional excretion of fluid, Na(+) and K(+) were not significantly different vs. CHL in P1, but significantly increased in P2 (P1: 1.5+/-0.2%, 1.1+/-0.2%, 31+/-3%; percent change in P2: 122+/-23, 128+/-21 and 29+/-6 respectively; each p<0.05 vs. P1). In conclusion, mice under both anesthetic regimens present reasonable and stable blood pressure and reasonable kidney function, but kidney reabsorption is more stable under CHL than under TBB anesthesia, which may facilitate study of the response in kidney function to acute interventions.

Anesthesia↗
PubMed2004

Near monochromatic X-rays for digital slot-scan mammography: initial findings.

X-ray spectra are composed of a broad bremsspectrum and anode-characteristic emission lines. In mammography typically molybdenum (Mo), rhodium (Rh) or tungsten (W) anodes are used in combination with Mo, Rh or aluminium filters. Only the photons with energies between 17 and 22 keV of the resulting spectrum are suitable for the soft tissue imaging needed for mammography. The aim of this article is to present first results obtained with a monochromator module mounted at the exit of the X-ray tube of a conventional clinical mammography unit. The experimental setup consists of a Siemens Mammomat 300, an X-ray monochromator module and a linear array detector for image acquisition. The technique is similar to the slot-scan technique known from digital mammography. The experimental machine allows to obtain images both with polychromatic and monochromatic X-rays. Initial evaluation of the system was performed by examination of a contrast-detail phantom (CD-MAM-phantom, Nijmegen, The Netherlands). Images done with the new monochromatic technique were compared to images of the phantom done with polychromatic spectra, with film-screen mammography as well as with digital mammography. The new technique with monochromatic slot-scan mammography resulted in correct identification of 93% of the phantom. Digital slot-scan mammography with polychromatic beam resulted in correct identification of 87%, digital full-field mammography in 83% and conventional film-screen mammography in 70% of the phantom. The results suggest that monochromatization has a potential for improving image quality or decreasing dose in X-ray mammography.

Equipment Design↗
PubMed2004

Functional consequences at the single-nephron level of the lack of adenosine A1 receptors and tubuloglomerular feedback in mice.

Mice deficient for adenosine A1 receptors (A1AR) lack tubuloglomerular feedback (TGF). In vivo micropuncture experiments were performed under anesthesia in A1AR-deficient and wild-type littermate mice to study the effects of chronic absence of A1AR on fluid and Na(+) reabsorption along the nephron, as well as the functional consequences at the single-nephron level of the lack TGF. Evidence is provided for an A1AR-mediated tonic inhibition of Na(+) reabsorption in a water-impermeable segment of the loop of Henle, possibly the thick ascending limb. In contrast, proximal tubular reabsorption of fluid, Na(+) and K(+) was unaffected by the chronic absence of A1AR. Experiments in which artificial tubular fluid was added to free-flowing late-proximal tubules demonstrated an essential role of A1AR/TGF in the stabilization of fluid and Na(+) delivery to the distal nephron. Further, the occurrence of spontaneous oscillations of hydrostatic pressure in proximal tubule ( P(PT)) at a frequency of about 32 mHz depended on intact A1AR/TGF. In comparison, the normal, stabilizing reduction in P(PT) following the initial rise in P(PT) during sustained small increases in proximal tubular flow rate does not require A1AR/TGF; TGF-independent mechanisms appear to compensate in this regard for a lack of TGF under physiological conditions and the lack of TGF is unmasked only when supraphysiological flow rates overwhelm TGF-independent compensation.

Animals↗
PubMed2004

Direct measurement of BDP and 17-BMP in bronchial and peripheral lung tissue after inhalation of HFA- vs CFC-driven aerosols.

Indirect assessments have shown a superior lung deposition of HFA-BDP (Ventolair/Qvar) compared to CFC-BDP (Aerobec). The aim of this study was to assess the concentrations of BDP and its metabolite 17-BMP in airways and peripheral tissue from resected lung specimens after inhalation of these BDP formulations. Immediately prior to surgery for lung cancer, 10 patients inhaled 1000 microg of either CFC-BDP (n = 5) or HFA-BDP (n = 5) Mouthwash was collected after inhalation, and serum before, during, and after surgery. There was no significant difference between CFC and HFA in the concentration of 17-BMP in bronchi (median, 4365 vs 4121 pg/g tissue). After CFC, concentrations of 17-BMP were lower in peripheral tissue (1424 vs 2089 pg/g; ANCOVA, p = 0.001) and in serum taken immediately after inhalation (688 vs 1219 pg/ml, p < 0.01). Furthermore, the CFC group showed a higher concentration of BDP in the mouthwash (17,660 vs 1320 ng/ml, p < 0.05), but the concentration of 17-BMP was lower (452 vs 1028 ng/ml, n.s.). These findings indicate a predominantly peripheral deposition of HFA-BDP, in line with previous data. They also provide evidence for a faster uptake and metabolism of HFA-BDP, probably because BDP is dissolved in HFA and has a smaller particle size distribution than the CFC suspensions.

Administration, Inhalation↗
PubMed2004

Evaluation of a wavelet-based computer-assisted detection system for identifying microcalcifications in digital full-field mammography.

PURPOSE: To evaluate a new wavelet-based computer-assisted detection (CAD) system for detecting and enhancing microcalcifications. MATERIAL AND METHODS: A total of 280 mammograms acquired by full-field digital mammography (Senographe 2000D; G.E. Medical Systems Milwaukee, Wisc., USA) were analyzed with and without a new wavelet-based CAD system for detecting and enhancing microcalcifications. The mammograms comprised roughly equal numbers of cases from each of the BIRADS (Breast Imaging, Reporting and Data System, according to the American College of Roentgenology) categories 1-5. Histologic confirmation was available for all of the 180 cases assigned BIRADS categories 3-5. Four readers interpreted all 280 images for suspicious microcalcifications using a scale of 1-5. The readers alternately assessed 5 images with and 5 without CAD. In a second reading immediately following the first, the readers had to reassess the 280 mammograms. The images that had already been interpreted without CAD were now presented with CAD and vice versa. The images were interpreted as soft copies on a diagnostic mammography workstation (Image Diagnost GmbH, Neufahrn/Munich, Germany). All images interpreted with CAD were presented with enhancement of microcalcifications by wavelet algorithms and prompting of microcalcifications. ROC (receiver operating characteristic) analyses were performed, and image interpretation time with and without CAD was measured. RESULTS: The overall time for interpretation required by all 4 readers together was 483 min with CAD compared to 580 min without CAD. ROC analysis revealed no significant advantage of CAD for the individual readers. Readers 3 (0.811/0.817) and 4 (0.799/0.843) had a slightly improved AUC (area under the curve) with CAD. Readers 1 and 2 had a slightly lower AUC with CAD (0.832 versus 0.861 and 0.818 versus 0.849). CONCLUSION: The CAD system significantly (P<0.05, t test) speeded up image interpretation with respect to the identification of microcalcifications, while the diagnostic quality remained almost identical under the study conditions.

Breast Diseases↗
PubMed2004

Exposure to house dust endotoxin and allergic sensitization in adults.

BACKGROUND: It has been suggested that exposure to elevated levels of endotoxin decreases the risk of allergic sensitization. OBJECTIVE: To examine the associations between current exposure to bacterial endotoxin in house dust and allergic sensitization in adults. METHODS: In 1995-1996, we conducted a nested case-control study following a cross-sectional study performed within the European Community Respiratory Health Survey (ECRHS). Data of 350 adults aged 25-50 years was analysed. Allergic sensitization was assessed by measurement of specific immunoglobulin E (IgE) against several inhalant allergens. Living room floor dust samples were taken. The endotoxin content was quantified using a chromogenic kinetic Limulus amoebocyte lysate test. RESULTS: Multiple logistic regression analysis showed a negative association between exposure to house dust endotoxin and severe allergic sensitization. Odds ratios (95% CI) adjusted for place of residence, gender, age, and 'caseness' were 0.80 (0.64-1.00) for sensitization to >/=1 allergen and 0.72 (0.56, 0.92) for sensitization to >/=2 allergens using 3.5 kU/l as a cut-off value for sensitization. With regard to single allergens, the protective effect of endotoxin was strongest for pollen sensitization [aOR (95% CI) = 0.74 (0.58, 0.93)]. CONCLUSION: Our results indicate that current exposure to higher levels of house dust endotoxin might be associated with a decreased odds of allergic sensitization in adults.

Adult↗
PubMed2004

The effect of adjustable dosing with budesonide/formoterol on health-related quality of life and asthma control compared with fixed dosing.

BACKGROUND: Budesonide/formoterol in a single inhaler is an effective therapy for asthma. We investigated whether adjustable maintenance dosing with budesonide/formoterol could maintain health-related quality of life (HRQL) and asthma control. PATIENTS/METHODS: Asthma patients (n = 4025) received budesonide/formoterol (Symbicort 160/4.5 microg) 2 inhalations twice daily (b.i.d.) for 4 weeks during run-in of this open, multicentre study. Patients were randomised to adjustable dosing (budesonide/formoterol 1 inhalation b.i.d.; stepping up to 2 or 4 inhalations bid for 1 week if asthma worsened) or fixed dosing (budesonide/formoterol 2 inhalations b.i.d.), for 12 weeks. Change in HRQL (standardised Asthma Quality of Life Questionnaire, AQLQ[S], score) during randomised treatment was the primary efficacy variable. Secondary variables included asthma control (peak expiratory flow [PEF], symptom-severity score, nocturnal awakenings, reliever-medication use) and study-medication intake. RESULTS: Clinically significant (> or = 0.5) improvements in AQLQ(S) score (mean 0.73), morning and evening PEF (mean 42.5 and 24.8 L/min, respectively), and symptom-severity score (mean 0.36) were achieved during run-in. The improvements were maintained in both groups although, overall, adjustable-dosing patients took fewer daily inhalations of budesonide/formoterol than fixed-dosing patients (mean 2.63 versus 3.82, p < 0.001). CONCLUSION: Adjustable maintenance dosing with budesonide/formoterol maintains HRQL and asthma control as effectively as fixed dosing and is associated with a reduced drug load overall.

Administration, Inhalation↗
PubMed2003

The effect of storage on allergen and microbial agent levels in frozen house dust.

BACKGROUND: House dust samples collected for exposure studies are often stored for variable time periods until analysis. However, there is currently no information on the effects of dust storage on the content of biocontaminants. Therefore, associations were analysed between the levels of mite allergens (Der p 1, Der f 1), cat allergen (Fel d 1) and microbial components (endotoxin, beta(1-->3)-glucan) on the one hand and the storage duration of dust samples at -20 degrees C on the other hand. METHODS: Within the framework of a study on the influences of INdoor factors and Genetics on Asthma (INGA), dust samples were collected from living room floors between June 1995 and August 1998 and extracted according to a standardized protocol. The concentrations of Der p 1, Der f 1, Fel d 1 and beta(1-->3)-glucan were determined with specific enzyme immunoassays. Endotoxin content was quantified using a chromogenic kinetic Limulus amoebocyte lysate (LAL) test. All concentrations were expressed per gram of dust RESULTS: Dust samples (n = 1236) were obtained from 655 homes in Hamburg, Hettstedt, Zerbst and Bitterfeld. Storage duration (range 8-298 days) was grouped into four categories ( 120 d). After adjustment for city of residence and season of dust sampling, means ratios comparing categories 2-4 to the first category were not statistically significant for Der p 1, Der f 1, endotoxin and beta(1-->3 glucan). However, Fel d 1 concentrations significantly declined with increased storage times of dust samples. CONCLUSIONS: Storage of house dust at -20 degrees C for up to 10 months has no effect on mite allergen, endotoxin and beta(1-->3)-glucan levels. A potential loss of Fel d 1 during storage of frozen dust samples needs further investigations by repeated measurements of allergen in identical dust samples.

Air Pollution, Indoor↗