N. Alima. Stephens College.
Devices of varying complexity have been used to reduce the most common sampling errors relating to particle size purchase 50 mg casodex fast delivery, wind velocity buy casodex 50 mg otc, and rain purchase casodex australia. Although many laboratories use various immunoassays to identify and quantify airborne allergens, the microscopic examination of captured particles remains the method of choice. Gravitational samplers were used historically, but are rarely used today because they provide qualitative data without quantitative data. Impaction Samplers Impaction samplers currently are the most common types of pollen samplers in use. The principle is that wind speed usually is greater than the rate of gravitational settling. Small particles carried by the wind have an inertial force that causes them to impact on an adhesive surface. Small surface areas, however, are rapidly overloaded, causing a decrease in the efficiency of capture. The rotating impaction sampler has two vertical collecting arms mounted on a crossbar, which is rotated by a vertical motor shaft. The speed of rotation is up to several thousand revolutions per minute and is nearly independent of wind velocity. These samplers usually are run intermittently (20 60 seconds every 10 minutes) to reduce overloading. In some models, the impacting arms are retracted or otherwise protected while not in use. Although suitable for pollens, they are more commonly used to measure smaller particles such as mold spores. Disorientation with wind direction and velocity skews the impaction efficiencies of particles of different sizes. For example, if the wind velocity is less than that generated by the sampler, smaller particles are collected in greater concentrations than exist in the ambient air. The Hirst spore trap is an inertial suction sampler with a clock mechanism that moves a coated slide at a set rate along an intake orifice. The Burkard spore trap collects particles on an adhesive-coated drum that takes 1 week to make a full revolution around an intake orifice. Spore traps are the most flexible devices for sampling particles over a wide range of sizes. The Anderson sampler is another suction device, but it is unique in its adaptability for enumerating viable fungal spores. Air passes through a series of sieve-like plates (either two or six), each containing 400 holes. The larger particles are retained by the upper plates and the smaller ones by successive lower plates. A Petri dish containing growth medium is placed beneath each sieve plate, and the spores that pass through the holes fall onto the agar and form colonies. This method has value for identifying fungi whose spore morphologic features do not permit microscopic identification. In general, however, nonviable volumetric collection techniques more accurately reflect the actual spore prevalence than do volumetric culture methods (15). The volume of air sampled is easy to calculate for suction devices because the vacuum pumps may be calibrated. In the case of rotation impaction samplers, there are formulas that depend on the surface area of the exposed bar of slide, the rate of revolution, and the exposure time. After the adherent particles are stained and counted, their numbers can be expressed as particles per cubic meter of air. Ground level is usually unsatisfactory because of liability, tampering, and similar considerations. The apparatus should be placed at least 6 m (20 feet) away from obstructions and 90 cm (3 feet) higher than the parapet on the roof. The methods of staining, enumerating, and calculating are beyond the scope of this discussion but are detailed in the references. This is often necessary because many spores are not morphologically distinct enough for microscopic identification. Most commonly, Petri dishes with appropriate nutrient agar are exposed to the air at a sampling station for 5 to 30 minutes. The plates are incubated at room temperature for about 5 days, then inspected grossly and microscopically for the numbers and types of colonies present. Potato-dextrose agar supports growth of most allergenic fungi, and rose bengal may be added to retard bacterial growth and limit the spread of fungal colonies.
Steroid sparing effect of nedocromil sodium in asthmatic patients on high doses of inhaled steroids purchase 50mg casodex overnight delivery. Nedocromil sodium in adults with asthma dependent on inhaled corticosteroids: a double blind cheap casodex on line, placebo controlled study purchase casodex 50mg free shipping. Does nedocromil sodium have a steroid sparing effect in adult asthmatic patients requiring maintenance oral corticosteroids? A double-blind study comparing the effectiveness of cromolyn sodium and sustained release theophylline in childhood asthma. Effects of the addition of nedocromil sodium to maintenance bronchodilator therapy in the management of chronic asthma. Nedocromil sodium versus theophylline in the treatment of reversible obstructive airway disease. Theophylline attenuation of airway response to allergen: comparison with cromolyn metered-dose inhaler. A comparison of inhaled albuterol and cromolyn in the prophylaxis of exercise-induced bronchospasm. Leukotriene antagonists and synthesis inhibitors: new direction in asthma therapy. Overexpression of leukotriene C4 synthetase in bronchial biopsies from patients with aspirin-intolerant asthma. Release of leukotrienes, prostaglandins, and histamine into nasal secretions of aspirin-sensitive asthmatics during reactions to aspirin. Effect of 5-lipoxygenase inhibition on bronchoconstriction and airway inflammation in nocturnal asthma. A controlled trial of the effect of the 5-lipoxygenase inhibitor zileuton, on lung inflammation produced by segmental antigen challenge in human beings. Eosinophil chemotaxis inhibited by 5-lipoxygenase blockade and leukotriene antagonism. Montelukast, a leukotriene receptor antagonist, reduces the concentration of leukotrienes in the respiratory tract of children with persistent asthma. Effect of zafirlukast (Accolate) on cellular mediators of inflammation: bronchoalveolar lavage fluid findings after segmental antigen challenge. Effect of a 5-lipoxygenase inhibitor on leukotriene generation and airway responses after allergen challenge in asthmatic patients. Inhibition of exercise-induced bronchospasm by zileuton: a 5-lipoxygenase inhibitor. The leukotriene receptor antagonist zafirlukast inhibits sulfur dioxide induced bronchoconstriction in patients with asthma. Efficacy and duration of the antileukotriene zafirlukast on cold air-induced bronchoconstriction. Effect of treatment with zileuton, a 5-lipoxygenase inhibitor, in patients with chronic asthma. Acute and chronic effects of a 5-lipoxygenase inhibitor in asthma: a 6-month randomized multicenter trial. Zafirlukast improves asthma and quality of life in patients with moderate reversible airflow obstruction. Therapeutic effect of zafirlukast as monotherapy in steroid-nave patients with severe persistent asthma. Long-term safety and efficacy of zafirlukast in the treatment of asthma: interim results of an open-label trial. A placebo-controlled, dose-ranging study of montelukast, a cysteinyl leukotriene-receptor antagonist. Montelukast for chronic asthma in 6- to 14-year old children: a randomized, double-blind trial. Low-dose inhaled fluticasone proprionate versus oral zafirlukast in the treatment of persistent asthma. Addition of zafirlukast compared with a doubled dosage of inhaled corticosteroids in asthmatic patients with symptoms on inhaled corticosteroids [Abstract]. Randomised, placebo controlled trial of effect of a leukotriene receptor antagonist, montelukast, on tapering inhaled corticosteroids in asthmatic patients. Leukotriene antagonist prevents exacerbation of asthma during reduction of high-dose inhaled corticosteroid. A randomized controlled trial comparing zileuton with theophylline in moderate asthma. Montelukast versus salmeterol in patients with asthma and exercise-induced bronchoconstriction. Two first-line therapies in the treatment of mild asthma: use of peak flow variability as a predictor of effectiveness. Pharmacodynamic and stereoselective pharmacokinetic interactions between zileuton and warfarin in humans, Clin Pharmacokinet 1995;29(suppl 2):67 76.
Patients with particularly informative genotypes and phenotypes often difficult or impossible to recognize in advance will typically be rare generic 50 mg casodex free shipping. Identification and recruitment of such patients in sufficient numbers to acquire clinically actionable information about their diseases will be possible only if molecular and clinical information can be combined in huge patient cohorts buy 50mg casodex with mastercard. Indeed purchase casodex 50mg, the suite of obstacles that a young investigator must overcome to penetrate this system are a major disincentive for involvement in patient-oriented research. In addition, the many talented biomedical researchers who choose to focus their work on model organisms (such as flies, worms, and mice) have little opportunity to share insights or collaborate with clinical researchers. The current biomedical training system separates researchers and physicians from the earliest stages of their education and creates silos of specialized, but limited knowledge. The insular nature of the current biomedical system does not encourage interdisciplinary collaborations and has significant negative effects on training, study design, prioritization of research efforts, and translation of new research findings. Long-term follow-up was not required to conduct the first generation of genotype-phenotype studies. However, questions such as Do cystic fibrosis patients with particular genotypes do better over a period of decades with particular treatments? Toward Precision Medicine: Building a Knowledge Network for Biomedical Research and a New Taxonomy of Disease 31 the results were generated, and whether the laboratory work was performed under protocols that permit results feedback. These limiting factors mean that most research results are not integrated into clinical care. Expert opinion on the duty to inform research participants of clinically relevant results vary widely. Indeed, many researchers are reluctant to contribute data to a common resource as it may expose them to questions about whether feedback to participants is necessary or desirable. In a sense, this challenge has parallels with the building of Europe s great cathedrals studies started by one generation will be completed by another, and plans will change over time as new techniques are developed and knowledge evolves. Many patients are already put on powerful drugs in their 40 s, 50 s, and 60 s that they will take for the rest of their lives. The very success of some cancer treatments is shifting attention from short-term survival to the long-term sequelae of treatment. For all these reasons, the era during which a genetic researcher simply needed a blood sample and a reliable diagnosis is passing. Outcomes research is also creating new opportunities for a close integration of medicine and data-intensive biology. Cost constraints on health-care services as well as an increasing appreciation of how often conventional medical wisdom is wrong has led to a growing outcomes-research enterprise that barely existed a few decades ago. The requirements of outcomes researchers for access to uniform medical records of large patient populations are remarkably similar to those of molecularly oriented researchers. Multiple Stakeholders Are Ready for Change The tremendous recent progress in genetics, molecular biology, and information technology has been projected to lead to novel therapeutics and improved health-care outcomes with reduced overall health-care costs. Clinical and basic researchers have learned that for their collective efforts to provide affordable improvements in health care, increased collaboration and coordination are required. Public-private collaborations are needed to combine longitudinal health outcomes data with new advances in technology and basic research. Such initiatives are essential to gain and apply the specific biological knowledge required to develop new approaches to treat and prevent disease. A dynamically evolving Knowledge Network of Disease would provide a framework in which a closer, more effective, relationship between clinical and basic researchers could thrive. Nowhere is the need for change more evident and urgent than in the pharmaceutical and biotechnology industries. Despite a massive increase in the amount of genomic and molecular information available over the past decade, the number of effective new therapies developed each year has remained stable, while the cost of developing each successful therapy has increased dramatically (Munos 2009). Toward Precision Medicine: Building a Knowledge Network for Biomedical Research and a New Taxonomy of Disease 32 large number of novel drug targets, an inadequate biological understanding of these targets has resulted in an ever-increasing failure rate of expensive clinical trials (Arrowsmith 2011a,b). The pharmaceutical and biotechnology industries are now leading proponents for developing public-private collaborations and consortia in which longitudinal clinical outcomes data can be combined with new molecular technology to develop the deep biological understanding needed to re-define disease based on biological mechanisms. Given the time scale on which private entities must seek return on investment, there is an increased willingness to regard much of this information as pre-competitive. Hence, the information itself, and the costs of acquiring it, must be widely shared. A major beneficiary of the proposed Knowledge Network of disease and New Taxonomy would be what has been termed precision medicine. Today, researchers look for relatively small differences between treated and untreated patients in trials that involve unselected patients, with little insight into the biological heterogeneity among the patients or their diseases. This approach requires a much larger number of patients, more time, and greater costs to assess the effectiveness of new therapies than would more targeted study designs. By using a precision-medicine approach to focus on those patients early in the drug-development process who are most likely to be helped, fewer side effects and reduced costs are likely to ensue. In such studies, compliance will likely be better, treatment duration longer, and therapeutic benefits more obvious than is the case with traditional designs. Greater therapeutic differences could also result in more efficient regulatory approval, and faster adoption by physicians and payers.
Hair itself is not an important allergen because it is not buoyant or water soluble cheap casodex 50 mg on-line. Water-soluble proteins of epidermal or salivary origin that are attached to the hair are important allergens 50mg casodex with mastercard, however casodex 50mg on-line. Desquamation is a continuous process for all animals, and the dander materials contain many water-soluble proteins that are highly antigenic and allergenic. People commonly develop local urticaria at the sites where they have been licked by a cat or dog or where they have been scratched by claws or teeth. All of these substances become part of the amorphous particulate matter of the air and are responsible for allergic morbidity. Cats seemingly produce the most dramatic symptoms in sensitive individuals, particularly in those who are exposed intermittently. Whether this is caused by the concentration of cat allergens in the environs or by the potency of the allergens is unknown. Studies with cat pelts have disclosed a substance called Fel d 1 that appears to be the major allergen, recognized by over 80% of cat-sensitive individuals ( 195). Allergens other than Fel d 1 in some sensitive individuals also have been detected in cat serum and urine, but these are minor allergens ( 198). Studies with individual cats show that some cats are high producers of allergen and others are not. Moreover, the rate of allergen production of individual cats varies from hour to hour. These factors may explain why some patients are more allergic to certain cats than to others ( 196). In addition, there does not appear to be any seasonal variation in Fel d 1 production. Morphologic room sampling shows abundant squamous cell fragments smaller than 5 m, enabling these fragments to reach small bronchioles and alveoli ( 199). This small particle size also explains why cat allergen can remain airborne in undisturbed conditions for extended periods. Serial dust samples collected in the study of 15 homes after removal of the family cats were analyzed for Fel d 1. After removing the cats, the levels decreased to those of control homes in 20 to 24 weeks. However, significant differences occurred in the rate of decline of Fel d 1 among homes. It may therefore be prudent to advise patients that it might take up to 6 months after removal of a cat for the bulk of the cat allergens to disappear from the home ( 200). In the same experiments, using dander from 13 breeds of dogs and sera of 16 patients with documented dog allergy, the various sera showed significant breed specificity. More recently Can f 1 and Can f 2 have been cloned and described as lipocalins, small ligand binding proteins (202). These patients have a high cross-reactivity with cat and other animal albumins ( 203). The fact that dogs tend to spend more time outdoors and are bathed more frequently may explain their decreased importance as an allergen source relative to cats. Most patients who are demonstrably sensitive to dander are also sensitive to other perennial allergens. This complicates the determination of which allergen is responsible for their symptoms. The recommendation to eliminate a pet from a home environment places the clinician in a difficult position. Patients do not readily accept the proposition that their pet may be the cause of their allergic problem, even in light of positive skin test results. Positive bronchial provocation might be supportive, but results are not conclusive. Cat allergen is known to persist in the home for up to 24 weeks after removal of the pet, so a trial separation of the patient away from the home environment for several weeks to months is probably the best prognostic indicator at this time. Horses resemble cats in the explosive symptoms that may occur on exposure to their dander, but this clinical situation is less common and less difficult to manage, primarily because of the absence of horse dander in the home. Some antigens are common to horse dander and serum, creating the potential for a serious problem in patients when horse serum (such as an antivenom) may be urgently needed. Equ c 1 and Equ c 2 have been cloned and both described as members of the lipocalin family ( 205,206). Significant skin test reactivity to the dander of rats and mice in persons whose homes are infested with these rodents also may be seen. Allergic symptoms in laboratory workers exposed to immune allergens have promoted several studies on the nature of these allergens ( 207,208).