The leading scientist in the production of new isotopes and elements was Glenn Seaborg generic zocor 20 mg without a prescription. Glenn Seaborg (1912 1999) Glenn Seaborg was a Swedish American (his mother was from Sweden) generic zocor 20mg mastercard. He also developed more than 100 atomic isotopes cheap zocor 40 mg line, like I-131 and Tc- 99m which are important isotopes for medicine. Seaborg was avarded the Nobel prize for Chem- istry in 1951 together with another Berkeley sci- entist Edwin McMillan. He used for the frst time a radioactive isotope in the treatment of a human disease (leukemia). John Lawrence became known as the father of nuclear medicine and Donner laboratory is considered the birthplace of this feld. Hal Anger (also a Donner man) invented in John Lawrence Hal Anger 1958 the gamma-camera also called Anger (1904 1991) (1920 2005) camera. This is also called Anger camera and consisted of a large fat scintilla- tion crystal and a number of photomultipliers. They used I-131 labeled insulin to measure the reaction between an antigen and antibody. David Kuhl 193 Some of the isotopes used in nuclear medicine The use of radioactive isotopes in research and medicine can be divided in three groups. Isotopes used as tracers A radioactive isotope attached to an important molecule can tell where it is. Isotopes emitting g-rays are easily observed, but also pure b-emitters like H 3 (tritium) and C 14 can be used. Thus, Melvin Calvin used C 14 to the exploration of photosynthetic carbon dioxide reduction. The Hershey Chase experiment A very well known experiment with radioactive tracers was the Hershey Chase experiment from 1952. Alfred Hershey and Martha Chase used the isotopes P 32 (b-emitter with half-life 14 days) and S 35 (b-emitter with half-life 87 days). Alfred Hershey (1908 1997) was the principal investiga- Numerous experiments within bio- tor, whereas Martha Chase (1927 2003) was the lab. Isotopes in radiation therapy In radiation therapy the purpose is to irradiate cancer cells to death and let the normal cells survive. Radium (Ra 226) was used from the beginning, both for teletherapy and as im- plants in brachytherapy. Attached to compounds (monoclonal antibodies) the isotope can be transported to the the cancer cells. Isotopes for diagnostic purposes Several isotopes emitting g-rays can, and have been used for diagnostic purposes. For example, I 131 will be accumulated in the thyroid and can via a gamma camera give information about sicknesses in the thyroid. We have pointed out before that the isotope most often used for medical information is Tc 99m. Thus, after the b-particle emission the newly formed technetium isotope is in a socalled meta- stable state. If we could isolate this metastable isotope it would be perfect for medical use, since the isotope would only emit a g-photon with no contamination from b-particles. Decay scheme for Mo-99 Mo 99 67 h The decay of Mo 99 results in a metastable nucleus de- noted Tc 99m. By emitting a g- photon it ends up in Tc 99 which is radioactive with a Tc 99 halfife of 213 000 years. The compound is rinsed with physi- ological saline, and the Tc-99m that has been formed follows the water it is like milking. The next step is to hook on this isotope to compounds that can bring it to particular places in the body that can be studied. Tc-99m emits -radiation with an energy of 140 keV, which readily escapes the body and is easily measurable. From a physicists point of view it is probably the technique developed to observe the distribution of radioactivity that is the most interesting whereas from a medical point of view it is the diagnostic power that is the most interesting. Ben Cassen and Hal Anger The technique with the radioactive isotopes in medical diagnostics started in the 1950s when Benedict Cassen invented the rectilinear scanner and in 1958 with the g-camera (or Anger camera). Blahd A picture of Hal Anger (1920 2005) and Benedict Cassen (1902 1972) at the International Confer- ence on Peaceful Uses of Atomic Energy in Geneva, Switzerland, in 1955. It can be mentioned that the Society of Nuclear Medicine every second year since 1994 give out a prize in honor of Benedict Cassen (The Benedict Cassen prize) for outstanding achievements in nuclear medicine. The illustration to the right demonstrate the technique introduced by Benedict Cassen. He assembled the frst auto- mated scanning system that was com- prised of a motor driven scintillation de- tector coupled to a relay printer. After the ini- tial studies, it was an extensive use of the scanning system for thyroid imaging during the early 1950s. Cassen s devel- opment of the rectilinear scanner was a defning event in the evolution of clinical nuclear medicine. In 1956, Kuhl and his colleagues developed a photographic attachment for the Cassen scanner that improved its sensitivity and resolution. With the development of organ-specifc radio pharmaceuticals, a commercial model of this system was widely used during the late 1950s until the early 1970s to scan the major body organs. The decline of the rectilinear photoscanner began in 1973 with the advent of computed axial tomography. As its name suggests (single photon emission), ordinary g-ray emission is the source for the information. The camera or detector rotates around the patient, and the detector will observe the tracer distribution for a variety of angles. After all these angles have been observed, it is possible to reconstruct a three dimensional view of the isotope distribution within the body. A computer is used to apply a tomo- graphic reconstruction algorithm to the multiple projections, yielding a 3-D dataset. An example with Tc 99m In the example shown (to the right), Tc-99m was added to methylene- diphosphonate, which is absorbed by the bone-forming cells (the osteo- blasts). The picture makes it possible to study diseases of the skeleton, such as bone cancer. In order to un- derstand this we refer to chapter 2 where we discussed the different ways an unstable nucleus could attain a more stable state. We mentioned that in the ordinary b-decay, a neutron was transformed into a proton and an electron, which was emitted. This is a favorable reaction since the neutron mass is lager than the proton mass. The opposite reaction where a proton is transformed into a neutron is how- ever, a more diffcult process. We can however, attain this goal via two different routes; 1) electron capture and 2) positron emission. For all natural isotopes, electron capture is the usual process because the energy between the par- ent and daughter is less than 2m c2 (m is the electron mass). However, for a number of artifcially e e induced isotopes positron emission takes place. The fate of the emitted positron is; after Illustration of the annihilation being slowed down, it will meet an elec- tron, and then either annihilate directly, or 511 keV photon form a short-lived positronium atom. The fnal process is an annihilation where the mass of the two particles is trans- formed into g-ray photons. A very important point is that the photons fy off in opposite directions (see the illustration to the right). We observe the two photons by detectors 180 degrees apart (coincidence measurements). We know Courtesy of Arnt Inge Vistnes from this observation that the annihilation process has taken place somewhere along the line shown in the illustration. One coincidence observation yield a line whereas two or more observations in other directions give a point (or a small area) where the radioactivity has its origin. Information on how tissue and organs functions on both the molecular and cell level. It is also possible to study changes in the brain that follows Alzheimer disease and epilepsy.
This issue arises specifically in the context of seeking material from deceased donors for research purchase 10 mg zocor mastercard. We commented earlier on the striking contrast between the national infrastructure established to maximise blood and organ donation generic zocor 20 mg free shipping, with the absence of any similar coherent structure in respect of gametes buy zocor 40mg line. However, we do not accept that these differences are sufficient to justify such a wholesale difference of approach. We conclude that there should be a coherent and managed infrastructure for egg and sperm donation, on the lines of the structures currently in place for organ donation. The precise shape or legal status of the infrastructure will be of much less importance than its overall aim of creating an organisational framework able to develop the best possible practice in handling all aspects of the recruitment of donors on behalf of clinics. In recommending the establishment of a pilot scheme to evaluate the effects of offering financial reward to those willing to come forward as egg donors for research (see paragraph 57), we noted that the risks of repeated egg donation are unknown, and potentially of concern, and that institutional protections within the system would be important. We recommend that an essential part of the pilot scheme should be the development of protections both to limit the number of times a woman may donate eggs for research purposes, and to guard against the inappropriate targeting of potential donors in other countries. The role of healthy volunteers in first-in-human trials has been considered in this inquiry primarily as a source of comparison with the donation of bodily material. We therefore limit ourselves to making the following observations with respect to two themes that have arisen earlier in this report: partnership and governance. We have suggested above that the recognition of a partnership between donors of bodily material and future users of that material may be valuable, especially in the context of long-term research studies. We suggest here that the concept of partnership may also be of some value in conceptualising the relationship between healthy volunteers in first-in-human trials and the researchers and institutions running the trial. If the research in question has been subject to ethical and scientific review and found to be satisfactory, then the key question for intermediaries is not whether it is appropriate to recruit participants at all, but rather whether there are particular ethical concerns about particular participants, or categories of participant. We further recommend that the National Research Ethics Service should consult on the possibility of limiting the total number of first-in-human trials in which any one individual should take part. There are all kinds of ways in which people become involved in the health of others. But there has to be something quite special about that involvement when it draws on other peoples own bodily material. In producing this report, the Working Party has tried to keep that sense of something special. The report received widespread recognition for its analysis of the ethical concerns arising in the use of human bodily material for a range of purposes, and for the framework it provided for those working 1 with such material. The regulatory landscape has altered beyond recognition, both in response to new scientific and clinical developments and in response to public opinion. Thus, even where consent was sought, there was a significant disjunction between what professionals understood parents to have consented to, and what those parents themselves understood. The particular distress caused by the retention of hearts of children who had died following surgery at 5 the Bristol Royal Infirmary demonstrated a further distinction between a clinical approach to tissue and that of patients and their families. From a clinical or scientific perspective a heart can be seen as a piece of machinery that has a key role in a living body, and no role in a dead one. From the non- 6 clinical perspective, however, hearts have many other meanings and associations. So do other parts of the body: it is striking that those who are willing to donate their kidneys for transplantation after 7 death may nonetheless withhold consent for other body parts, in particular hearts and eyes (corneas). Yet the demand for bodily material, whether for medical treatment or for research, remains as pressing as ever. Attitudes towards medicine and medical care have been changing as well, in the context of a general shift in society towards a greater focus on care of the self, and the role of the 11 patient in determining how health services should be delivered, and the increasing expectation that medicine will be able to intervene to overcome problems formerly regarded as insoluble. While the general shift in attitudes to health care may have led to a new kind of awareness of the body and its potential value to others, there is little evidence to suggest that this has discouraged people from donating freely: we note, for example, that organ donation is on the increase. We are dealing with an issue that does not seem to go away the demand for bodily material for medical treatment and research. However, bodily material is not like any other, and the question of how it is obtained and used raises all kinds of further questions. This is where, for instance, the unpaid and voluntary nature of donation comes in: why is this aspect valued, and what are the ethical concerns to which this emphasis has been the response? The Working Party was asked to identify and consider the ethical, legal and social implications of transactions involving human bodies and bodily material in medical treatment and research. It was also asked to consider what limits there should be, if any, on the promotion of donation or volunteering. See also: Nature Immunology Editorial (2010) Reduce, refine, replace Nature Immunology 11: 971. In this report we attempt to assist deliberation on these questions, and to throw light on the tensions that arise when it comes to reconciling public need with individual feelings on the matter. As one respondent to the consultation commented: Human biological samples can ultimately be provided only by individuals, not by organisations. If individuals do not accept that responsibility in sufficient 15 numbers, the current system will fail. We therefore highlight both the international dimension (for example where international statements or agreements exist) and examples of the diverse regulatory approaches taken in other jurisdictions. Nor do we consider the specific issues raised by genetic research, although our general comments on research using bodily material will in many cases also be relevant for genetic research. Rather, it has taken the view that much may be learned from comparing different forms of donation, their different regulatory structures, and the ethical assumptions that underpin these structures. Such comparisons 15 Professor Peter Furness, responding to the Working Partys consultation. If one factor that unites the many different forms of material covered in this report is that they have a 19 single source (the body of a person), another is that the desired outcome of these actions is benefit 20 to others, whether or not these others are in mind at the time. We have already noted possible distinctions between bodily material from living individuals and bodily material from deceased individuals; and, indeed, the way the law now makes relatively little distinction between these has been the subject of complaint by some clinicians. Other key distinctions relate to the inducements or incentives that are permissible in the context of encouraging people to participate in these forms of bodily donation, and to the degree of control that the donor may have over the future use of what has been donated. At first sight, there may appear to be very clear distinctions between the two cases that more than explain the regulatory differences. Such developments bring their own ethical challenges: in particular, they highlight the crucial role played by transactions and intermediaries in the sphere of donation. Diverse intermediaries (specialist nurses, transport services, technical and ancillary staff to name just a few) are involved in processing the material to facilitate its use by the end- recipient. Thus, while we note that potential donors are often encouraged to come forward by agencies focusing on the needs of a single symbolic recipient, any consideration of policy surrounding donation must take into account the complex transactions and multiple intermediaries involved in the process. The person providing the material may be living or deceased; the material may be used almost immediately or stored for long periods of time; the material may be used raw or heavily processed; the material may be used in the direct treatment of others or for research purposes; the recipient may be an individual patient, or research organisation; the material itself may be healthy or it may be diseased. For as long as bodily health is generally recognised as a marker of personal well-being, there will be a need for society to do what it can to promote the practice of medicine and pursue research into the functioning of the human body. This chapter provides an overview of these issues, and suggests that a comparative approach, identifying both similarities and distinctions in the nature and use of these materials, may help to illuminate and explain many of the ethical concerns that arise in connection with these practices. Any attempt to divide these various forms of bodily material into discrete categories is inevitably imperfect, given the complex and overlapping relationships between them. However, in this report we follow common non-clinical usage in separating out solid organs and blood from other forms of tissue. Donated blood may be used for research if not needed for treatment, and samples of blood will often be taken during medical investigations, as part of a clinical trial or other research project, or in the context of population or longitudinal studies (see paragraphs 1. Blood is classified into four main groups, and giving 28 someone blood from the wrong group may be life-threatening. Plasma may also be processed into a range of medical products, including immunoglobulins (antibodies) to provide protection from disease for patients with low levels of antibodies, coagulation factors (to improve blood clotting) and albumin (used for restoring blood volume). While such material can be deployed in many ways, and may undergo modification, it can only be obtained from a person. Small quantities of adult stem cells are found in organs, tissues and fluids such as heart, brain and fat, as well as in cord blood. Adult cells of various kinds, for example skin cells, can also be transformed into pluripotent stem cells by the introduction of the factors found to be active in embryonic stem cells (see paragraph 1. Adults who volunteer to donate stem cells through the bone marrow registries may either donate stem cells from circulating blood (which involves being injected with a drug to increase significantly the number of stem cells in the circulating blood), or bone marrow itself, which involves the removal of stem cells from hip bones under general 35 anaesthesia. It is also possible to donate some organs during life: at present the organs provided by living donors are primarily kidneys, but liver lobes may also be donated, and partial donations of the lung have taken place in the past. Tissue donated for transplantation after death is governed by the same rules as organs: it enters a common pool to be used according to need and its use cannot be directed to a particular individual. Tissue donated by a living person may theoretically be donated to benefit another specific person but in practice this will not generally be necessary, and hence the donated 39 tissue will be for general use. Tissue transplants range from life-saving treatment (for example in the treatment of catastrophic 42 burns) to cosmetic enhancement (for example penis or breast enlargement).
Study members who scored uated the association between informant reports of Big Five per- low on Conscientiousness and low on Openness to Experience sonality traits measured at baseline and physical health measured were in poorer physical health at age 38 years (see Table 7 discount zocor 20mg, Model at age 38 (Model 1) zocor 10 mg sale. Results were robust to all three estimation obesity (Model 5) cheap zocor 10 mg amex, global self-reported health (Model 6), self- procedures. We also present the results of a cohort s health declined from age 26 to age 38, t(854) 13. The scale places each occupation into 1 of 6 categories (from 1, unskilled laborer to 6, professional) on the basis of educational levels and income associated with that occupation in data from the New Zealand census. Self-reports of health Global self-reported Self-reported health at age 26 years was assessed with the first 0. Item scores were linearly transformed to create an overall index ranging from 100 (no limitations)to0(severe limitations) (McHorney et al, 1994). The family medical history score is the proportion of a Study member s extended family with a positive history of disorder, summed over all disorders. Incident rate ratios are based on Poisson regressions, controlling for sex, using the composite index of poor physical health at age 38 as the outcome measure. Second, individual Taken collectively, these results confirm the importance of Conscien- differences in Neuroticism consistently did not predict physical health. These results also highlight two Here, we address factors that may have contributed to these results. Accumulating evidence linking analyses provide an additional robustness test of health prediction intelligence to health and longevity (Deary et al. Because personality rat- son & Deary, 2004) suggests that one way in which Openness to ings were performed by a nurse and receptionist, these analyses Experience may contribute to health is via its overlap with intel- also serve to illustrate the potential utility of brief personality ligence. We tested this by substituting the age-38 measure of clinically measured health Discussion with Study members global appraisals of their health at age 38 This article suggests that we need to broaden the definition of (Ware & Sherbourne, 1992). Neuroticism assessed by nurse ratings viduals would develop poor health in the ensuing 12 years. We was not associated with poor health in the bivariate model, but was associated with poor health when controlling for baseline health. In con- recognize that acquiring informant reports from peers and family trast, Neuroticism as assessed by receptionist ratings was not associated members who know an individual well may pose some practical with health in either the bivariate model or after controlling for baseline challenges in primary-care settings. The table displays the association between age-26 personality and age-38 poor health, controlling for childhood intelligence. The scale was reverse coded so that a higher score equals poorer self-reported health. Realistically, the complexities of translating contributes to health take shape across the life course and are molecular targets into actionable medical guidelines mean that this intertwined with individuals daily decisions to engage in activities goal is more distant than previously anticipated (Ioannidis, 2009). Five-item informant ratings of an individual s Con- Previous studies have convincingly shown that self-reports of scientiousness and Openness to Experience when Study members Conscientiousness predict health outcomes. Our analysis dem- were young adults could foretell their physical health at age 38, onstrates that these associations are not dependent on the source adding incremental prognostic information even after accounting of personality measurement. Third-party observers, both those who for measures routinely ascertained in primary care settings. Even knew Study members well and those who did not, were able to more powerfully, informant ratings of Conscientiousness and rely solely on externally expressed cues to identify the charac- Openness to Experience predicted decline in physical health over teristic features of an individual s Conscientiousness in a man- a 12-year period. Moreover, fleeting encounters with Study mem- ner that is predictive of health decline. In addition to bolstering bers provided enough of an impression for the Study nurse and the evidence base that individual differences in Conscientious- receptionist to make personality assessments that provide prognos- ness are likely the most salient of the Big Five personality tic value in predicting Study members health. These staff impres- dimensions to contribute to overall health, our research also sions of Conscientiousness and Openness to Experience at zero demonstrates that (at least in regards to predicting health) acquaintance yielded similar predictive utility as informant reports accurate measurement of Conscientiousness does not require despite differences in Study member age at personality assessment privileged access to the self. Our findings suggest that integrating personality likely impacts health processes in a manner similar to intelligence measurement into primary care may be an inexpensive and acces- (Gregory, Nettelbeck, & Wilson, 2010). Our analysis suggests that sible way to identify which young adults are in need of their assessing Openness to Experience may be a simple and accessible doctors attention to promote a healthy lifestyle while they are yet window into attributes of intelligence associated with future health young, in time to prevent disease onset. Accumulating research shows that low intelligence is linked to a broad array of health outcomes such as cancer, cardiovascular Why Do Conscientiousness and Openness to disease, and all-cause mortality (Batty & Deary, 2004; Batty, Experience Predict Health? People higher in intelligence ness are more likely to engage in active lifestyles and maintain are likely to have knowledge conducive to preventing age-related healthy diets (Bogg & Roberts, 2004). This may explain the mixed findings for Openness to Experience in predicting health outcomes when measured using self-reports. Previous research has suggested that observer reports may result in more accurate pre- diction of Openness to Experience/Intellect and result in more unique predictive validity (Vazire, 2010). In regards to health prediction, observer ratings of low Openness to Experience were consistently predictive of poorer physical health. The prospective utility of Neuroticism for predicting health outcomes is a matter of ongoing debate. There is broad consensus that Neuroticism predicts health complaints and health service use (B. There is less consensus about whether Neuroticism predicts objectively measured health (Costa & Mc- Crae, 1987; Watson & Pennebaker, 1989). In the present study, neither informant nor staff ratings consistently predicted objective poor health. These results should be interpreted in reference to research about what type of person- ality information is captured in observer ratings versus self-reports. Although observer reports rely on externally expressed cues, self- reports have privileged access to an individual s thoughts and feelings. It has been argued that this distinction may result in asymmetry between self- and observer reports for traits such as Neuroticism (Vazire, 2010). We did not collect self-reports of Big Five personality traits, and so we could not compare health pre- diction between observer- and self-reports of personality directly. Although we demonstrate that observer ratings of personality predict future health, we do not rule out the potential of self-report measures to provide equally valuable inferences. Thus, although the association between Neuroticism and health appears less robust than Conscientiousness, the extent to which self-reports of Neu- roticism predict objective health remains an open question. First, we did not collect self-reports of Big Five personality and thus could not directly compare the predictive utility of observer ratings with self-report ratings. Rather, we relied on a substantial literature demonstrating links between self-reported personality and health to serve as the reference point for our examination of observer-reported person- ality and health. Second, the personality effects we report are small, but these should be evaluated relative to other well-established risk factors for poor health. Adding However, all of the clinical indicators reported here are well personality measures to electronic infrastructures of health records characterized and have prognostic utility as early warning mea- could provide an invaluable data resource for researchers to ex- sures for morbidity and mortality (Blair et al. Randomized controlled trials should be dimensions (Benet-Martnez & John, 1998; McCrae & Terrac- conducted in which health care providers either have access to ciano, 2005) suggests that findings from New Zealand should personality information or not. There is countries where healthcare is less accessible and accessing it ongoing debate about how to address behavioral risk factors for requires greater conscientious effort. Our findings suggest that interventions requiring effortful Next Steps planning, self-control, and strict adherence are less likely to be effective for segments of the population in which these psycho- Healthcare reform in the United States is leading to a substantial logical resources are in shortest supply (i. This rapid increase presents a timely opportunity for health- individuals low in Conscientiousness may increase the appeal of care professionals to encourage young adults to supplant the health health-promotion communication, and the effectiveness of health- risk behaviors of youth with health-promoting habits for midlife. Self-reports have known social desirability biases, and such effects may be com- pounded if patients were to complete personality questionnaires References knowing that the outcome could affect the type of medical treat- ment they would receive. Intelligence, personality, and ratings were not guaranteed, would reporters self or other be interests: Evidence for overlapping traits. Personality structure: Emergence of the five-factor cultures and ethnic groups: Multitrait-multimethod analyses of the Big model. Conscientiousness and health-related behaviors: A meta-analysis of the leading behavioral contributors to British Journal of Health Psychology, 17, 85 102. Is personality associated with health care use by older Evidence and implications for a personality trait marker of health and adults? The disease-prone person- s12160-012-9454-6 ality : A meta-analytic view of the construct. Conscientiousness and longevity: An examination of possible personality-targeted prevention program for adolescent alcohol use and mediators. Neuroticism, somatic complaints, agreement of personality judgments at zero acquaintance. Self-rated health and mortality: A disease: Prospective study and updated meta-analyses. Personalized genetic prediction: Too limited, too as predictors of illness and death: How researchers in differential psy- expensive, or too soon? The Big Five trait taxonomy: History, Actual causes of death in the United States, 2000.
This is inherent in being a physician 20 mg zocor sale, where the challenge is to aid individuals with their problems zocor 20mg low cost. It is important to maintain a sense of respect and understanding for our patients generic zocor 20 mg otc. By training the ability to truly listen and understand what the patient is experiencing, the physician can wisely and firmly respond. A systematic approach to the psychoanalytic treatment of narcissistic personality disorders. Management of this disorder, which accounts for approximately 16 million patient visits per year, has changed dramatically in the past 50 years. This is due to new insights into the pathophysiology of sinusitis, advances in rhinoscopy (nasal endoscopy), improved radiographic imaging, and availability of antibiotics ( 1). Technical advances in endoscopic instrumentation have defined a new era in the office diagnosis and surgical management of sinusitis, permitting an unprecedented level of precision. Understanding the indications as well as the technical limitations of diagnostic and therapeutic rhinoscopy is now essential for practitioners who manage chronic sinusitis. Hirschman performed the first fiberoptic nasal examination using a modified cystoscope ( 2). Messerklinger of Graz began to use this technology for systematic nasal airway evaluation. He reported that primary inflammatory processes in the lateral nasal wall, particularly in the middle meatus, result in secondary disease in the maxillary and frontal sinuses ( 2). Messerklinger found that small anatomic variations or even minimal inflammatory activity in this area could result in significant disease of the adjacent sinuses as a result of impaired ventilation and drainage. With this observation, he used endoscopes to develop a surgical approach to relieve the obstruction in such a way that normal sinus physiology was preserved. Specifically, he demonstrated that even limited surgical procedures directed toward the osteomeatal complex and the anterior ethmoid air cells could relieve obstruction of drainage from the frontal and maxillary sinuses. This philosophy was markedly different from the ablative sinus procedures advocated in the past, such as Caldwell-Luc, in that cilia and sinus mucosal function were preserved. The ethmoid sinus develops into a labyrinth of 3 to 15 small air cells; however, the other sinuses exist as a single bony cavity on each side of the facial skeleton. The ethmoid and maxillary sinuses are present at birth and can be imaged in infancy. The frontal sinuses develop anatomically by 12 months and can be evaluated radiographically at 4 to 6 years. Sphenoid sinuses develop by the age of 3 but cannot be imaged until a child is 9 or 10 years of age. The point at which mucosal outpouching occurs persists as the sinus ostium, through which the sinus drains ( 3). Diagnostic rhinoscopy offers a wealth of information regarding the distribution of inflammatory foci within the sinonasal labyrinth and the associated anatomic variations that may impair physiologic sinus drainage. It is usually performed in an office setting with the aid of topical decongestants and topical anesthesia. It is essentially an extension of the physical examination that helps confirm the diagnosis, gain insight into the pathophysiologic factors at work, and guide medical or surgical therapy. The principles of diagnostic and therapeutic rhinoscopy are based on a firm understanding of the anatomy and physiology of the nose and sinuses (Fig. The lateral nasal walls are each flanked by three turbinate bones, designated the superior, middle, and inferior turbinates. The region under each turbinate is known respectively as the superior, middle, and inferior meatus. The frontal, maxillary, and anterior ethmoid sinuses drain on the lateral nasal wall in a region within the middle meatus, known as the osteomeatal complex. This is an anatomically narrow space where even minimal mucosal disease can result in impairment of drainage from any of these sinuses. The sphenoid sinus drains into a region known as the sphenoethmoidal recess, which lies at the junction of the sphenoid and ethmoid bones in the posterior superior nasal cavity. The nasolacrimal duct courses anteriorly to the maxillary sinus ostium and drains into the inferior meatus. The ethmoid bone is the most important component of the osteomeatal complex and lateral nasal wall. It is a T-shaped structure, of which the horizontal portion forms the cribriform plate of the skull base. The vertical part forms most of the lateral nasal wall and consists of the superior and middle turbinates, as well as the ethmoid sinus labyrinth. A collection of anterior ethmoid air cells forms a bulla, which is suspended from the remainder of the ethmoid bone, and hangs just superiorly to the opening of the infundibulum into the meatus. The drainage duct for the frontal sinus courses inferiorly such that its ostium lies anterior and medial to the anteriormost ethmoid air cell. Therefore, the main components of the osteomeatal complex are the maxillary sinus ostium/infundibulum, the anterior ethmoid cells/bulla, and the frontal recess. The infundibulum and frontal recess exist as narrow clefts; thus, it is possible that minimal inflammation of the adjacent ethmoidal mucosa can result in secondary obstruction of the maxillary and frontal sinuses. The paranasal sinuses are lined by pseudostratified-ciliated columnar epithelium, over which lays a thin blanket of mucus. The cilia beat in a predetermined direction such that the mucous layer is directed toward the natural ostium and into the appropriate meatus of the nasal airway. This is the process by which microbial organisms and debris are cleared from the sinuses ( 4). This principle of mucociliary flow is analogous to the mucociliary elevator described for the tracheobronchial tree. The maxillary ostium and infundibulum are located superior and medial to the sinus cavity itself. Therefore, mucociliary in the maxillary sinus must overcome the tendency for mucus to pool in dependent areas of the sinus. Antrostomies placed in dependent portions of the sinus are not effective because they interfere with normal sinus physiology. Pathophysiology of Chronic Sinusitis The American Academy of Otolaryngology Head and Neck Surgery Task Force on Rhinosinusitis defines sinusitis as a condition manifested by an inflammatory response involving the following: the mucous membranes (possibly including the neuroepithelium) of the nasal cavity and paranasal sinuses, fluids within these cavities, and/or underlying bone ( 5). Rhinosinusitis, rather than sinusitis, is the more appropriate term, because sinus inflammation is often preceded by rhinitis and rarely occurs without coexisting rhinitis. Primary inflammation of the nasal membranes, specifically in the region of the osteomeatal complex, results in impaired sinus drainage and bacterial superinfection, resulting in further inflammation ( Fig. In most patients, a variety of host and environmental factors serve to precipitate initial inflammatory changes. Host factors include systemic processes such as allergic and immunologic conditions, various genetic disorders (e. Host variations in sinonasal anatomy also occur, predisposing some to ostial obstruction with even minimal degrees of mucosal inflammation. Neoplasms of the nose and maxilla and nasal polyps also may cause anatomic obstruction. The pathophysiology of chronic sinusitis can be influenced by sinonasal anatomy, infection, and allergic/immunologic disorders. Rhinoscopy can provide significant insight into the relative importance of these elements in an individual patient. The infectious, allergic, and immunologic elements of chronic sinusitis are typically subjected to intense pharmacologic treatment. A failure of these therapies may indicate the need for surgery in the management of this problem. Septal or turbinate pathology can create narrow meatal clefts such that even minimal mucosal inflammation results in ostial obstruction and initiation of the cascade of events resulting in chronic sinusitis. Accessory maxillary ostia may result in recirculation of mucus with diminished net drainage. Infection Sinusitis is often preceded by an acute viral illness such as the common cold ( 5). This leads to mucosal swelling, obstruction of sinus outflow, stasis of secretions, and subsequent bacterial colonization and infection ( 6). These include resolution, progression with adverse sequelae such as orbital or intracranial infection, development of silent chronic sinusitis, or the development of symptomatic chronic sinusitis. In the chronic persistent state, microbial colonization and infection lead to additional inflammation, further exacerbating the process. With the development of symptomatic chronic sinusitis, multiple bacteria are usually cultured, including anaerobes and b-lactamase producing organisms ( 7,8).
I. Jerek. Maine Maritime Academy. 2019.
Richmond Rascals. 12 Richmond Hill. Richmond-Upon-Thames. TW10 6QX tel: 020 8948 2250