By F. Mufassa. Golden State Baptist College. 2018.
It is differential attenuation of photons in the body that produces the contrast which is responsible for the information purchase 20mg protonix mastercard. The attenuation of the radiation in the body depends upon; the density cheap protonix 40 mg without a prescription, the atomic num- ber and the radiation quality discount protonix 40 mg on-line. In mammography one are interested in visualizing small differences in soft tissue and we use low energy x-rays (26 28 kV) to enhance the tissue details. In the case of chest pictures the peak energy must be larger because the absorbing body is very much larger and some radiation must penetrate the body and reach the detector. It is the transmitted photons that reach the detector that are responsible for the picture. The detector system A number of different detectors (flm, ionization chambers, luminescence and semiconductors) have been used since the beginning of x-ray diagnostic. The x-ray picture was created when the radiation was absorbed in the flm emul- sion consisting of silver halides (AgBr as well as AgCl and AgI). In the usual morning meeting the doctors were often gath- ered in front of the light box to discuss the patients (see illustration). Consequently, in order to increase the sensitiv- ity, intensifying screens were introduced. The screen is usually a phosphor scintillator that converts the x-ray photons to visible light that in turn expose the flm. The introduction of intensifying screens was made already in 1896 by Thomas Alva Edison. He introduced the calcium tungstate screens which were dominating up to the 1970-ties. We do not intend to go through the technical details with regard to intensifying screens nor to the many technological details within x-ray diagnostic. In order to ensure that the photoelec- tric effect is dominant lower energies are used. Energies lower than 30 kV are used for mammog- raphy which is very effective for seeing details in soft tissue. However, this energy range is only useful for tissue thicknesses of a few centimeter. Mammography X-ray tube In mammography the goal is to see the contrast between different den- sity of soft tissue, fat and blood ves- sels without use of contrast media. The x-ray energy is between 25 and 30 kV in order to ensure that the photoelectric effect is dominant. This also result in absorption of ra- diation and an increase of the patient dose. Detector 181 Examples Tumor It is sometimes very convincing to see a mammogram like that shown to the right. It is also amazing that we can see details like this in soft tissue without using contrast media to enhance the difference in electron density. To the left is a modern digital picture whereas the other is a flm-based mammography. Implants Muscle It is obvious, even for the layman, that the presence of breast implants does interfere and makes it more diffcult to obtain good information with mammography. The presence of implants affects the way mammograms are done, since additional views are needed during routine screening mammography to visualize all of the breast tissue. The lesson to learn from this is that implants could be an impediment to cancer detection. Implant We can conclude that you have to be well trained to give a good de- scription. In order to re- duce the dose to the doctors the fuorescent screen was backed by lead glass. This examination (in Norway known as gjennomlysning ) was widely used in the treatment of lung tuberculosis and pneumothorax treatment. The x-rays were con- verted to light by using phosphors (CsI:Na) and again to photoelectrons. They were accelerated and focused on a smaller fuorescent screen which in turn is coupled to a re- corder system; for exam- ple a video camera or a flm camera. If the technique is coupled with the use of contrast media it is possible to follow the contrast when it is fowing through the blood vessels. Shoe-ftting fuoroscopy Today it is almost unbelievable that x-rays was used to fnd the right pair of shoes. However, during the period 1930 1950 an x-ray fuoroscope like the one shown was used. The system consisted of a vertical wooden cabinet with an opening near the bottom into which the feet were placed. When you looked through one of the three viewing ports on the top of the cabinet (e. When you put your feet in the opening, you were standing on top of the x-ray tube. Measurements made in recent years indicate that the doses to the feet were in the range 0. Analog to digital converters and com- puters were adapted to conventional fuoroscopic image intensifer systems. Angiographic procedures for looking at the blood vessels in the brain, kidneys, arms and legs, and the blood vessels of the heart all have benefted tremendously from the adaptation of digital technology. It is reasonable to assume that all of the flm systems will be replaced by digital x-ray detectors. The digital images can be archived onto compact disks and thus save storage space. The digital images can be retrieved from an archive at any point in the future for refer- ence.
Information technology is the key contributor to the technological convergence the Committee perceives protonix 40mg for sale. In medicine order protonix 40 mg mastercard, information technology offers perhaps the best hope of increasing efficiency and improving our collective learning about what works and what does not buy discount protonix 20mg. In a mere 20 years, people have made the transition from regarding most human knowledge as locked away in the dusty backrooms of research libraries to expecting it to be at their finger tips. Understandably, the public is losing patience with barriers to the sharing and dissemination of information. The social-networking phenomenon is a particularly dramatic illustration of changing attitudes toward information and associated blurring of the line between the public and private. The Committee recognizes that some aspects of the world we envision are more readily approachable than others. As emphasized throughout this report, there are many impediments to progress along the path we outline. That is the reason the Committee recommends pilot projects of increasing scope and scale as the vehicle for moving forward. Although we consider the creation of an improved classification of disease valuable in its own right, we do not recommend a crash program to pursue this goal in isolation from the broader reforms we emphasize. We regard smaller projects on the recommended path as preferable to larger, narrower initiatives that would distract attention and resources from these reforms. We think the impediments can best be overcome and the optimum design of the Information Commons, Knowledge Network, and the New Taxonomy best emerge in the context of pilot projects of increasing scope and scale. Toward Precision Medicine: Building a Knowledge Network for Biomedical Research and a New Taxonomy of Disease 66 Even some stakeholders in the health-care system who find the Committee s basic vision compelling may ask whether or not a special, organized effort is required to achieve the Committee s goals. In particular, some might argue that there are already enough examples many have been cited in this report in which data-intensive laboratory tests have such clear benefits for patients that the traditional system of test development and insurance reimbursement will allow a smooth transition to a new era of molecular medicine. Indeed, there is real risk of a backlash against premature claims of the efficacy of genomic medicine (Kolata 2011). The key to avoiding such a backlash is development of a robust system for discovering applications that have real clinical benefits and validating those claims through open processes. The Committee believes that expecting or pressuring payers in the health-care system to bear the costs of integrating data-intensive biology and medicine without clear evidence of the safety, efficacy, and economic feasibility of particular applications would fail indeed, such an effort could easily be counter-productive. On the other hand, as some of the scenarios sketched above indicate, the Committee believes that a well planned public investment in creating the system the Committee envisions would lead relatively quickly to robust public-private partnerships that would allow all stakeholders to build on early successes. Perhaps even more importantly, the Committee believes that its approach offers the most realistic available path to ultimate sustainability of precision medicine. Public investment in research can play an essential role in building a solid foundation for precision medicine, but it cannot sustain its dissemination: precision medicine will only become a routine aspect of health care when it pays its own way. To bring the discussion back to the Committee s core mission, we close by re- emphasizing our view toward disease taxonomy. Accurately and precisely defining a patient s condition does not assure effective treatment, but it is unequivocally the place to start. However, the Committee believes that implementation of its core recommendations would bring many new allies to the cause of improving this patient s health prospects and would equip these diverse players with powerful new tools and resources that are unlikely to emerge without an organized effort to create them. Medium-term exposure to traffic-related air pollution and markers of inflammation and endothelial function. Distinct types of diffuse large B-cell lymphoma identified by gene expression profiling. Physical activity and endometrial cancer in a population-based case-control study. Toward Precision Medicine: Building a Knowledge Network for Biomedical Research and a New Taxonomy of Disease 68 Biesecker, L. The ClinSeq project: Piloting large- scale genome sequencing for research in genomic medicine. The effect of altitude change on anemia treatment response in hemodialysis patients. Surveillance Sans Frontires: Internet-based emerging infectious disease intelligence and the HealthMap project. Rapid identification of myocardial infarction risk associated with diabetes medications using electronic medical records. Interactions between genetic variants and breast cancer risk factors in the breast and prostate cancer cohort consortium. Self-reported racial discrimination, response to unfair treatment, and coronary calcification in asymptomatic adults: The North Texas Healthy Heart study. Toward Precision Medicine: Building a Knowledge Network for Biomedical Research and a New Taxonomy of Disease Caspi, A. Genetic sensitivity to the environment: The case of the serotonin transporter gene and its implications for studying complex diseases and traits. Genome-wide methylation profile of nasal polyps: Relation to aspirin hypersensitivity in asthmatics. Time to move from presumptive malaria treatment to laboratory-confirmed diagnosis and treatment in African children with fever. Tobacco Smoke Causes Disease: The Biology and Behavioral Basis for Smoking-Attributable Disease. Molecular mechanisms and clinical pathophysiology of maturity-onset diabetes of the young.
Nevertheless order protonix 20mg fast delivery, serologic tests and nasopharyngeal or sputum cultures were positive for viruses in 23 of 29 (80%) adult patients who reported a recent respiratory tract infection and were hospitalized for asthma (10) buy cheap protonix 20mg on line. Overall buy protonix 20 mg with visa, 37% of adults admitted for asthma had reported a recent respiratory tract infection ( 10). Fortunately, pharmacologic therapy can minimize the effects of these nonspecific triggers. The approximate risk for an allergic-type disease in a child is 20%, but if one parent is allergic, this risk increases to 50% ( 17,18 and 19). If both parents are allergic, there is a 66% chance of the child developing an allergic condition ( 17,18 and 19). In a prospective study of children evaluated during the first 6 years of life, the risk for a boy developing asthma was 14. These data support the notion of polygenic inheritance with greater prevalence in boys. In twin studies, the concordance for asthma in monozygotic twins reared together was similar to that for twins reared apart ( 21). In addition, in a study of 5,864 twins who were evaluated from infancy to age 25 years, the cumulative incidence of asthma was 6% in males and 5. If one twin developed asthma, the relative risk of the co-twin developing asthma was 17. More than 80% of cases of asthma began by 15 years of age, when nearly all of the study subjects lived in the same home environment (22). Methacholine responsiveness, total serum IgE concentration, and immediate skin test reactivity have been found to be more concordant in monozygotic twins than in dizygotic twins ( 23), which supports a genetic influence over an environmental influence. Both factors should be considered as contributory, and production of specific antiallergen IgE appears to be affected by environmental and local allergic exposures in the genetically susceptible subject. The onset of early childhood asthma has and has not been associated with parental smoking ( 20,24). However, once asthma begins, evidence exists for increased childhood respiratory symptoms from passive smoking ( 25,26 and 27) or actively by the adolescent who smokes (26). Frick and co-workers ( 28) demonstrated development of antiallergen IgE in association with increasing antiviral antibodies in a prospective study of high-risk infants whose parents both had allergic diseases. Indoor allergen exposures from house dust mites ( 31), cats (32), and cockroaches (33) have been associated with the development of asthma, emphasizing that both viral infections ( 27) and allergens are involved in emergence of childhood asthma. New-onset asthma in older men (aged 61 years or older) was associated with detectable serum IgE antibodies to cat allergen but not dust mites, ragweed, or mouse urinary antigen ( 34). In this study, IgE antibodies to dog dander and cockroach excreta were not measured. By age 12 years, 58% of the children had developed positive (10 mm in duration) responses to tuberculin testing, and 36% of children had reported atopic symptoms ( 35). Asthma symptoms and atopy were associated negatively with positive tuberculin responses, and presence of tuberculin reactivity was associated with remission from asthma by years 6 or 12 ( 35). The latter stems from data revealing less atopy when there was a previous episode of measles (37). The notion that asthma is an epidemic in the absence of infection has been suggested ( 38) and might be supported by the finding that house dust containing endotoxin (which activates macrophages) was associated with wheezing in infants (39). Collagen synthesis may result from stimulation or injury to airway epithelial cells ( 46). The key cell is the myofibroblast, which is a hybrid cell of fibroblast and smooth muscle cell origins. The increased metabolic activity of epithelial cells appears to contribute to airway damage and remodeling. Human bronchial epithelium from patients with asthma express Fas ligand (Fas L) and Fas on eosinophils and T lymphocytes ( 49). Biopsy samples from patients who had not received inhaled corticosteroids had reduced numbers of apoptotic eosinophils and reduced expression Fas L and Bcl-2, which help regulate apoptosis. Conversely, inhaled corticosteroid treated patients had fewer eosinophils and increased numbers of apoptotic eosinophils (49). These findings are consistent with a persisting inflammatory cell infiltrate that characterizes asthma. Eosinophil cationic protein has been identified in areas of denuded bronchial epithelium. Mast cells in the bronchial lumen and submucosa are activated, and their many cell products are released, whether preformed or synthesized de novo. Macrophages, lymphocytes, and epithelial cells participate as well, as mentioned earlier. Evidence supports the concept of neuroimmunologic abnormalities in asthma, such as the lack of the bronchodilating nonadrenergic noncholinergic vasoactive intestinal peptide in lung sections from patients with asthma ( 58). Substance P concentrations in induced sputum have been reported to be markedly elevated, compared with that in controls (59). The free radical nitric oxide is known to be detectable in expired air in patients with asthma, and its concentration increases further after allergen challenge ( 60). A free radical generated from arachidonic acid, 8-isoprostane, is increased in asthma and reflects ongoing oxidative stress ( 61). There are progressively greater amounts in expired air as asthma severity increases from mild to severe ( 61). These findings demonstrate the complexity of asthma, which decades ago was considered a psychological condition. Acute asthma is the most common childhood medical emergency (67), with a distinct subset of patients (16%) accounting for 36% of emergency department visits ( 68). Often, adults and children requiring acute treatment of asthma have not received or are not using optimal antiinflammatory therapy.
Additional features suggesting upper airway obstruction include stridor buy protonix 20mg, normal oxygenation proven protonix 40mg, and resolution of airflow obstruction after intubation (43) generic protonix 20 mg online. Antibiotics are frequently prescribed for asthmatics with increased sputum production. However, sputum that looks purulent in asthma contains eosinophils, not polymorphonuclear leukocytes, and antibiotics are of no benefit in this setting ( 44). Antibiotics should be reserved for treatment of concurrent sinusitis, or when mycoplasmal or chlamydial infections are suspected. Noninvasive lower extremity Doppler ultrasonographic examinations are helpful when they indicate thrombus; however, results of lower extremity Doppler studies are negative in 30% to 40% of patients with acute pulmonary embolism. Serial lower extremity Doppler studies provide an added sense of security, but the utility of this approach has not been validated in this setting. Ventilation-perfusion scans are difficult to interpret if there is airflow obstruction, but still may be diagnostic. Examination of the head and neck should focus on identifying barotrauma and upper airway obstruction. Prolongation of inspiration, stridor, and suprasternal retractions suggest upper airway obstruction. Tracheal deviation, asymmetric breath sounds, mediastinal crunch, and subcutaneous emphysema suggest pneumomediastinum or pneumothorax. Rarely, tracheal deviation is caused by atelectasis from mucus plugging, foreign body aspiration, or endobronchial tumor. The mouth and neck should be inspected for mass lesions or signs of previous surgery such as tracheostomy or thyroidectomy. However, wheeze is not a reliable indicator of the severity of airflow obstruction ( 48). A silent chest indicates severe obstruction, with insufficient flow for wheezes to occur. Heart rate generally decreases in improving patients (although some improving patients remain tachycardic because of chronotropic effects of medications). Supraventricular and ventricular arrhythmias occur, particularly in the elderly ( 50). The finding of a third heart sound, jugular venous distention, or pedal edema suggests primary heart disease. Jugular venous distention is a manifestation of dynamic hyperinflation, forceful exhalation, and tension pneumothorax. In severely dyspneic patients, peak flow determination is generously deferred because it rarely alters initial management and may worsen bronchospasm ( 53), even to the point of respiratory arrest ( 54). Several studies have demonstrated that failure of initial therapy to improve expiratory flow after 30 minutes predicts a more severe course and need for hospitalization ( 55,56,57 and 58). The presence of hypercapnia denotes severe disease; however, it alone is not an indication for intubation. Conversely, the absence of hypercapnia does not rule out impending respiratory arrest ( 61). Patients who waste serum bicarbonate in response to persistent respiratory alkalosis develop a metabolic acidosis with a normal anion gap. Lactic acidosis is more common in men, severely obstructed patients (62,63), and patients receiving parenteral b agonists ( 64). In mechanically ventilated patients, serial blood gases help guide ventilator management. Chest Radiography Chest radiographs influence treatment in 1% to 5% of cases ( 65,66 and 67). In one study (68) that reported radiographic abnormalities in 34% of cases, the majority of findings were classified as focal parenchymal opacities or increased interstitial markings, common indicators of atelectasis in asthma. The available data suggest that radiography is indicated only when there are localizing signs or symptoms, concerns regarding barotrauma or pneumonia, or when it is not clear that asthma is the correct diagnosis. In mechanically ventilated patients, chest radiography confirms proper endotracheal tube position. Observation for at least 60 minutes after the last dose of b-agonist helps ensure stability prior to discharge. Before discharge, patients should receive written medication instructions as well as a written plan of action to be followed in the event of deterioration. Mild cases with a complete response to bronchodilators may be considered for inhaled steroids alone. Most patients do well with oral steroids, particularly if they had not been optimally treated prior to the emergency room visit (69). An 8-day course of 40 mg/day prednisone is as efficacious and safe as an 8-day tapering schedule ( 70). Alternatively, a single dose of triamcinolone diacetate 40 mg intramuscularly also has been reported to be as effective as prednisone 40 mg/day for 5 days after treatment in the emergency room for asthma ( 71). Patients in this group require ongoing treatment either in the emergency room or general medical ward. Physicians should err on the side of admission when there is a harmful home environment and when directly observed therapy is needed in noncompliant patients. This practice improves oxygen delivery to peripheral tissues such as respiratory muscles, reverses hypoxic pulmonary vasoconstriction, and may result in bronchodilation. Oxygen also protects against the decrease in Pa O2 resulting from b agonist induced pulmonary vasodilation and increased blood flow to low V/Q units ( 72,73).