By J. Javier. The Johns Hopkins University.
Key Points Necrotizing ulcerative gingivitis⎯treatment: • intense oral hygiene; • remove predisposing factors; • mechanical debridement; • metronidazole order cephalexin 500 mg line. For example cephalexin 250mg on line, in 1993 purchase cephalexin 250mg fast delivery, 26% of 5-year-olds had some signs of gingivitis discount 500mg cephalexin with mastercard, and the proportion increased to 62% at the age of 9. The prevalence of gingivitis peaks at about 11 years and then decreases slightly with age to 15 years. In terms of gingivitis, there has been no improvement over the decades between surveys. Indeed, in 1993, between 11 and 14% more children of all ages between 6 and 12 years had signs of gingivitis when compared with 1983. These differences were not maintained with increasing age, however, as 52% of 15-year- olds had gingivitis in 1993 compared with 48% in 1983. Furthermore, there were no differences between 1983 and 1993, in the proportion of 15-year-olds with pockets between 3. These data suggest that the gingival condition of children in the United Kingdom has deteriorated over the 10 years between 1983 and 1993, whereas the periodontal status of 15-year-olds has not changed. Certainly, changes in gingival health do not mirror the dramatic improvement in the prevalence of caries over the same period. This trend was reversed by 1993 when between 10 and 20% more children of all ages had plaque deposits. The onset of puberty and the increase in circulating levels of sex hormones is one explanation for the increase in gingivitis seen in 11-year-olds. Oestrogen increases the cellularity of tissues and progesterone increases the permeability of the gingival vasculature. Oestradiol also provides suitable growth conditions for species of black pigmenting organisms which are associated with established gingivitis. Histopathology The inflammatory infiltrate associated with marginal gingivitis in children is analogous to that seen in adults during the early stages of gingival inflammation. The dominant cell is the lymphocyte, although small numbers of plasma cells, macrophages, and neutrophils are in evidence. Research findings have not yet determined unequivocally whether the lymphocyte population is one of unactivated B cells or is T-cell dominated. The relative absence of plasma cells, which are found in abundance in more established and advanced lesions in adults, confirms that gingivitis in children is quiescent and does not progress inexorably to involve the deeper periodontal tissues. Key Points Chronic gingivitis: • plaque-associated; • lymphocyte-dominated; • complex flora; • linked to the onset of puberty. Microbiology The first organisms to colonize clean tooth surfaces are the periodontally harmless, Gram-positive cocci that predominate in plaque after 4-7 days. After 2 weeks, a more complex flora of filamentous and fusiform organisms indicates a conversion to a Gram-negative infection, which, when established, comprises significant numbers of Capnocytophaga, Selenomonas, Leptotrichia, Porphyromonas, and Spirochaete spp. These species are cultivable from established and advanced periodontal lesions in cases of adult periodontitis. This suggests that the host response (rather than the subgingival flora) confers a degree of immunity to the development of periodontal disease in children, thus preventing spread of the contained gingivitis to deeper tissues. Manual versus powered toothbrushes The treatment and prevention of gingivitis are dependent on achieving and maintaining a standard of plaque control that, on an individual basis, is compatible with health. Toothbrushing is the principal method for removing dental plaque, and powered toothbrushes now provide a widely available alternative to the more conventional, manual toothbrushes for cleaning teeth. There is considerable evidence in the literature to suggest that powered toothbrushes are beneficial for specific groups: patients with fixed orthodontic appliances⎯for whom there is also evidence that powered toothbrushes are effective in reducing decalcification; children and adolescents; and children with special needs. It remains questionable whether children who are already highly motivated with respect to tooth cleaning will benefit from using a powered toothbrush. A systematic review evaluating manual and powered toothbrushes with respect to oral health has made some important conclusions. Compared to manual toothbrushes, rotating/oscillating designs of powered toothbrushes reduced plaque and gingivitis by 7-17% although the clinical significance of this could not be determined. Powered brushes, therefore, are at least as effective and equally as safe as their manual counterparts with no evidence of increased incidence of soft tissue abrasions or trauma. No clinical trials have looked at the durability, reliability, and relative cost of powered and manual brushes so it is not possible to make any recommendation regarding overall toothbrush superiority. Gingival enlargement occurs in about 50% of dentate subjects who are taking the drug, and is most severe in teenagers and those who are cared for in institutions. The gingival enlargement reflects an overproduction of collagen (rather than a decrease in degradation), and this may be brought about by the action of the drug on phenotypically distinct groups of fibroblasts that have the potential to synthesize large amounts of protein. Phenytoin-induced enlargement has been associated with a deficiency of folic acid, which may lead to impaired maturation of oral epithelia. Approximately 30% of patients taking the drug demonstrate gingival enlargement, with children being more susceptible than adults. There is evidence to suggest both a stimulatory effect on fibroblast proliferation and collagen production as well as an inhibitory effect on collagen breakdown by the enzyme collagenase. It is also given to post-transplant patients to reduce the nephrotoxic effects of cyclosporin.
The discoveries of genomic science can be used to build a new set of tools so that doc- tors can measure and predict how a patient will respond to immunosuppressive drugs cheap cephalexin 750 mg with amex. With such tools cephalexin 500 mg sale, transplant physicians could monitor patients regularly to make sure their treatment is always optimal cephalexin 750 mg with amex. In fact cheap cephalexin 750mg with mastercard, these same tools could also guide therapy of patients with diabetes, systemic lupus, rheumatoid arthritis and other immune-related diseases. The basis of this approach is that there may be some genetic “signature” within donors and recipients that predict the best course of treat- ment following a transplant surgery. This signature could be within the tissues of the transplanted organ or in the blood cells. An example of application of personaliza- tion of immunosuppression is kidney transplantation. Role of Immunological Biomarkers in Monitoring Grafted Patients Following transplantation of major organs such as heart, kidney, and liver, rejection of grafted organs is an important problem. There is a need for non-invasive tests to monitor these patients for adjusting their immunosuppressive drug treatment and early detection of rejection. A sentinel signature has been characterized raising the possi- bility of application of blood leukocyte expression signatures for assessment of immune status and early detection of disease. With the advancement of many high-throughput ‘omics techniques such as genomics, proteomics, and metabolomics, efforts have been made to understand potential mechanisms of speciﬁc graft injuries and develop novel biomarkers for acute as well as chronic rejection (Sarwal 2009). Microarrays are being increasingly used to identify speciﬁc patterns of gene expression that predict and characterize acute and chronic rejection, and to improve the understanding of the mechanisms underlying organ allograft dysfunction. It is feasible to develop minimally invasive, rapid tests for prognosis and diagnosis in personalized management of transplanta- tion patients. The test, which is available to clinicians, can determine the risk a patient may have for further complications, and thus physicians will be able to adjust ther- apy to the degree of risk, rather than treating every patient in exactly the same way. Improved Matching of Blood Transfusion Blood transfusions are among the earliest forms of personalized therapies because the blood groups of the donor and recipient are matched. Whilst blood transfusions are inherently safe with the compatibility between the donor and the recipient being tested using serological techniques, there is a signiﬁcant section of the population that suffer serious illness and side effects after receiving multiple transfusions of blood that is not a perfect match. These patients develop antibodies after some time that reject imperfectly matched blood transfusions, a process known as alloimmuni- zation, which can lead to serious illness and life-threatening side effects. Bloodchip will provide the medical community with a much clearer picture of the many different and often small variations in blood types, thereby allowing more accurate matching of donors and recipients. The new test will be of real beneﬁt to patients who currently receive multiple blood transfusions and require a perfect match in blood types. The Bloodchip test will literally be a life saver for those who suffer from illnesses that require multiple blood transfu- sions such as hemophilia, sickle cell disease and thalassemias by ensuring that the patients receive perfectly matched blood to enable them to better manage their con- ditions. Bloodchip has been widely accepted by the medical community and will become the new standard for the test- ing of blood types in course of time. Individualized monitoring of drug bioavailability and immunogenicity in rheumatoid arthritis patients treated with the tumor necrosis factor alpha inhibitor inﬂiximab. Pharmacogenetics as a tool for optimising drug therapy in solid-organ transplantation. Universal Free E-Book Store 564 17 Personalized Approaches to Immune Disorders Hronová K, Šíma M, Světlík S, et al. Personalized medicine in rheumatoid arthritis: is the glass half full or half empty. Licensing of natural killer cells by host major his- tocompatibility complex class I molecules. Pharmacogenomics of antirheumatic drugs and personalized medicine for rheumatoid arthritis. Universal Free E-Book Store Chapter 18 Personalized Approaches to Miscellaneous Problems in Healthcare Personalized Management of Diabetes Worlwide prevalence of diabetes mellitus is ~347 million. Personalizing the management of diabetes according to the patient’s individual pro- ﬁle can help in improving therapy adherence and treatment outcomes. E-health solutions can be used to improve process efﬁciencies and enable remote access. Decision support tools and algorithms can help physicians in making therapeutic decisions based on individual patient proﬁles. Accurate biomarker tests to identify people at risk for diabetes could enable targeted and individualized prevention efforts. Identiﬁcation of these variants has not yet led to new, individualized prevention methods. Further research is needed to identify genomic and other types of bio- markers that could accurately predict risk and facilitate targeted prevention. Advances in pharmacogenomics have led to the identiﬁcation of polymor- phisms that affect the expression and function of drug-metabolizing enzymes and drug transporters, as well as drug targets and receptors. For difﬁcult cases, leukocytapher- esis, beclomethasone dipropionate, anticytokines and other new therapies are tried. Advancement of genome analysis might have an impact on the treatment of inﬂammatory bowel diseases.
M A T E R I A L S A N D M E T H O D S Studies were carried out using a standard Jaszczak S P E C T pha n t o m and patient data wer e acquired according to standardized protocols using a Siemens Orbiter g a m m a camera and transferred to Nuclear Diagnostics workstations for analysis buy 500mg cephalexin visa. T h e technique described here has been implemented using the X W i n d o w System (trademark of the Massachusetts Institute of Technology) running on a S u n w o r k station (Sun Microsystems cheap 750mg cephalexin visa, Inc cephalexin 500 mg for sale. It m a k e s use of the software library routines ‘N U C L I B ’supplied by Nuclear Diagnostics Ltd cheap cephalexin 750 mg without prescription. These library routines provide structures to facilitate the input/output, m e m o r y storage and display of nuclear medicine image data. T h e basic premises of this m e thod are that a r a w data set contains all the infor mation necessary to characterize the distribution of radioactivity in three dimensions and that, for a given data set, it is possible to describe the relationships between the entire set of projections as a set of mathematical functions. O n c e this description is made, it is possible to manipulate the data set to predict clinically advantageous ‘what if scenarios that maintain the relationships and provide quantitative parameters. A user defined seed pixel within this object starts off a three dimensional edge detector that produces a series of discrete points defining the boundaries that satisfy a preset target range and edge sharpness, and terminates w h e n all such points have been identified. A least squares fit to this set of edge pixels defines the boundary of the object according to an assumed ellipsoid or irregular shape selected by the user. T h e algorithm then forms an estimate of the outline of the patient’s bod y according to a preset threshold from the limits as seen in all the projections, and also the m e a n background counts free fro m all other major objects. Next, a copy of the delineated object as well as the estimated body outline is produced in a n e w data set to f or m the basis of the forward projection simulation module. T h e pixels within the b o d y out line are given an initial count value based on the estimate of the m e a n background, and the pixels within the object of interest are given an arbitrary initial count value by the user. These counts are then forward projected by a M o n t e Carlo subroutine that isotropically distributes these initial estimates of counts per voxel for each projection angle. This subroutine takes into consideration the aforementioned attenu ation m a p s (and any additional attenuation corrections if required), noise, m o dula tion transfer function and time variance of activity within the segmented organ due to pharmacokinetic redistribution or radionuclidic decay. A chi-squared statistic is calculated to c ompare the simulated data with the actual data based o n the projections with the majority of the counts arising from the object of interest, and used to revise the initial estimates iteratively. This procedure converges to a point w h e n the simula tion mirrors the original data closely for only the delineated object independent of all others. A t this point, the algorithm can branch in one of t w o w a y s by either deleting the segmented object fro m the r a w data set or keeping the object but deleting every thing else, i. This decision is m a d e by the user based o n the clinical situation for which the study w a s performed. T h e quantitative data about the object, namely the volume, activity and time variance during the period of acquisition are inferred f rom the values of these parameters used during the simulation to get the m i n i m u m chi-squared statistic. All the above steps and their resultant output can be overridden or modified by the user should the need be felt. T h e entire sequence is repeated several times until all objects of interest have been segmented and quantitated independently of each other using the r a w data set only, and a n e w data set is generated that includes the appropriate objects of interest only, in any combination dictated by the clinical situation. In its present state of development, the algorithm terminates at this point without attempting to f o r m images. Currently, the n e w data set which contains the quantitated objects is reconstructed using back projection with no prefiltering and a simple r a m p filter to obtain images for comparison with conventionally filtered and reconstructed images. Further refinements of the algorithm and validation of the results are currently under consideration. R E S U L T S Because of space limitations, only a small selection of results and images can be presented here. Please note that the colour table s h o w n is cyclic due to conversion fro m S u n workstation format colour images to P C format black and white images. In all images, the patient’s anterior is at the top, and patient’s right is o n the left of the image. Table I gives quantitative data for a pha n t o m with six spheres, ranging in v o l u m e from 0. Figure 2 shows a conventionally back projected reconstruction of a transverse section at the level of the kidneys of an m In-octreotide study using no prefiltering and a simple r a m p filter. Figure 3 shows a hybrid image with both the kidneys and spleen f r o m the original data placed in the estimated b o d y outline, while Fig. Figure 5 shows the final iteration showing the s a m e section with the right kidney completely r e m o v e d from the r a w data set without affecting the left kidney or the spleen. It can be seen that the artefactual cold area in the area between the kidneys is reduced. Figure 6 shows a transverse section of a conventional post-reconstruction image at the level of the bladder in a " T c m labelled C Y T - 3 5 1 study of prostate cancer at 24 h with W e i n e r prefiltering and attenuation correction, while Fig. Conventionally back projected reconstruction of a transverse section at the level of the kidneys of an 1,1In-octreotide study using no prefiltering and a simple ramp filter. Hybrid image with both the kidneys and spleen from the original data placed in the estimated body outline. Final iteration showing the right kidney completely removed from the raw data set without affecting the left kidney or the spleen.
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