Bioactive materials are available buy 80 mg super levitra with visa, hav- important part of the restoration of form and func- ing therapeutic activities ranging from anti-microbial order cheap super levitra line, tion in patients treated for trauma purchase super levitra 80mg overnight delivery, craniofacial can- to promotion of mineralization order 80mg super levitra with visa, to the enhancement of cers, or other abnormalities. The evidence base for the survival of the Computer-directed materials processing and the endosseous dental implant is extensive and has been collection and manipulation of three-dimensional recently reviewed (Cochran, 1996; and Fritz, 1996). Computer-assisted fabrication systems fully and partially edentulous patients has been based in the dental laboratory allow for delivery of clearly demonstrated in longitudinal studies prostheses based on titanium or polycrystalline (Albrektson et al, 1988; Spiekermann et al, 1995; ceramics, such as alumina and zirconia. While The human periodontal diseases are a group of most evidence is available for titanium implants, there inflammatory disorders that affect the supporting is evidence to support the use of hydroxyapatite and tissues of the teeth. Periodontal diseases result from titanium plasma sprayed implant surfaces (Cochran, the host response to the bacterial infection of the 1996; and Fritz, 1996). The classifica- support the use of both two-stage and one-stage tion of periodontal diseases was recently modified implant systems (Cochran, 1996; and Buser et al, and now includes eight disease categories 1988). The major disease categories are tional prosthodontic techniques combined with the gingival diseases (plaque-induced and non-plaque- application of tooth-sparing dental materials. In some tory response as evidenced by increased production patients inflammatory gingivitis can exist for many of inflammatory mediators. A recent that lead to the transition of gingivitis to periodonti- report by Tomar and Asma calculated that 41. Greater extent and severity of periodontitis have been The currently accepted model for progression of associated with both type 1 and type 2 diabetes. Recent periodontitis consists of periods of disease activity studies have begun to define the molecular mechanisms and inactivity. The binding of tooth site is variable and can be dependent on many advanced glycation endproducts in the periodontium to factors including identifiable risk factors as well as their receptor on macrophages, endothelial cells, and the sensitivity of the technique used for measuring other structural cells can induce a hyperinflammatory change (Armitage, 1996). The prevalence of moderately severe to severe periodontitis is remarkably consistent in different x Digital radiography. The prevalence of early-onset Diagnostic tests have been developed that identi- forms of periodontitis ranges between 0. The host response can be Risk Assessment and Diagnosis assessed by analysis of gingival crevicular fluid, sali- va, or blood. A num- accepted as a routine part of patient management ber of risk factors for periodontitis have been iden- (Lamster, 1997; and Kaufman and Lamster, 2000). Recently, however, the results from epidemiologic studies x Plaque removal by the patient, and professional have shown a relationship between severe oral infec- plaque and calculus removal in the dental office; tions, especially periodontal diseases, and other health problems: atherosclerosis, heart attacks, x Use of chemotherapeutic agents (such as essential strokes, chronic obstructive pulmonary disease, and oils, cetylpyridium chloride, and chlorhexidine) premature births. For example, it appears that peri- delivered in toothpastes, mouth rinses, and occa- odontal disease may increase the risk of dying from sionally by oral irrigation devices; a heart attack or having a stroke. New studies are shedding light on how periodon- x Host-modulating agents to decrease the inflam- tal organisms cause damage beyond the periodontal matory response (low-dose doxycycline, which has pocket. These organisms are capable of entering the been shown to block the action of matrix metallo- bloodstream and can target certain organs, such as proteinases). The surgical treatment of periodontal disease has Three key organisms that are closely associated focused on the elimination/reduction of excessive with periodontal diseases, Porphyromonas gingi- probing depths. There is considerable interest in valis, Treponema denticola, and Bacteroides surgical procedures that promote regeneration of forsythus, have been implicated in the periodontal lost periodontal tissues: infection-systemic disease relationship. They do not colonize easily and require a lush biofilm ecosystem x Placement of barrier membranes to promote re- to support adherence, growth, and emergence. These organisms have 1999); special enzymes and proteins that enable them to trigger mild host inflammation and enhanced gingi- x Allogeneic and xenogeneic bone grafts (Nasr et al, val crevicular flow to ensure an adequate food and 1999); and, nutrient supply from the serum. These organisms target the liver and activate the hepatic acute phase x Xenogeneic enamel matrix proteins that rely on response. Other human studies show no are exposed to similar oral pathogens during their association, but there are supportive data from ani- lifetime. This hypothesis does Chronic Obstructive Pulmonary Disease and not necessarily negate the potential importance of Aspiration Pneumonia oral infection as a contributor to systemic diseases, however, it points out that there may be underlying Data from case-control studies and population mechanisms not yet identified that may better explain surveys suggest that periodontal pathogens shed the observed associations between periodontal dis- into the saliva can be aspirated via the bronchia to eases and other systemic conditions. The more severe the periodontal dis- ease status of the patient the greater the apparent Five longitudinal studies have shown that pre- risk for aspiration pneumonia. Furthermore, the existent periodontitis, as determined by direct oral mature periodontal flora can serve as a habitat for examination, independently confers excess risk for respiratory tract pathogens, especially in hospital- increased morbidity or mortality due to cardiovas- ized individuals with dysphagia secondary to stroke cular disease. The increased risk ranges from a (Scannapieco and Mylotte, 1996) and during pro- modest 20% (odds ratio 1:2) to 180% (odds ratio longed intubation. Another study demonstrated a dose-response ratory pathogens in these compromised individuals relationship between periodontitis and death caused appears to increase the risk for pulmonary involve- by myocardial infarction and stroke (Beck et al, ment (Scannapieco, 1999). Many epi- Pregnancy Outcomes demiologic studies have confirmed that diabetes is strongly associated with periodontitis, with an odds Case-control and prospective human studies sug- ratio in the range of 2-3. The metabolic stress of infection shifts a adjacent maxillary alveolus, or alveolus and palate, typ- person with normal glucose tolerance towards a ically in the vicinity of the lateral incisor. Complete lip, alveolar and ments are underway to definitively determine palate clefts represent approximately 50% of all clefts. Animal Models x Syndromic clefts involve the presence of one or Animal models of infections with periodontal more physical and/or mental/neurological patterns of pathogens and experimental periodontitis have abnormalities in addition to the cleft. The presence demonstrated the deleterious effect of infection on of minor anomalies or of major anomalies that might atherosclerosis, diabetes, and fetal growth (Collins be unrelated to the etiology of the cleft occasion- et al, 1994a; and Lalla et al, 1998). About 30% of only help establish biological plausibility but also orofacial cleft cases are attributed to the over 350 provide important clues regarding the mechanisms syndromes recognized to date. Purely environmental causes are relatively rare, and Oral clefts are classified and distinguished into even these may be affected by genetic differences two major types based on whether the palate only influencing metabolism of teratogens following versus the lip or both the lip and palate are involved maternal and fetal exposures. This classification reflects the embryologi- a monogenic autosomal dominant or recessive or X- cally distinct events of closure of the lip versus linked mode of transmission, 15% involve chromoso- closure of the palate. These two major types of mal rearrangements, about 5% have primarily an clefting are caused by substantially different environmental (i. The specif- evidence suggests that some overlap in etiology ic gene defects for some of the monogenetic syn- also exists. Genes for other syndromes, such as van der palate only, posterior to the incisive foramen. Woude, have been mapped to a small chromosomal They may affect the soft palate only, or both hard region, and gene identification is expected soon. This category includes submu- The causes of nonsyndromic orofacial clefting cous cleft palate where the cleft affects the mus- involve complex gene-environment interactions culature of the soft palate but with intact overlying (Schutte and Murray, 1999; and Carinci et al, mucosa. These studies figures do not account for the psychosocial impact have either been consistently negative, inconsistent of the disease on patients and their families, a com- among studies, or account for a tiny fraction of the ponent of the disease for which treatment may be heritable risk of nonsyndromic orofacial clefting. It insufficient even in developed countries (Turner et appears that six or more genes probably have major al, 1998). The lack of advanced medical services, effects on susceptibility, though none of these have including surgery, often unavailable in undeveloped been convincingly identified and independently countries, contributes to substantial morbidity and replicated to date (Prescott et al, 2000). Variation at mortality and to even greater psychosocial stress on dozens of other genes probably contribute smaller patients living with unrepaired oral clefts. Exposure to smoking, alcohol there are very strong financial and humanitarian and certain prescription medicines such as anticon- incentives to reduce the frequency of oral clefts both vulsants during pregnancy increases risk (Gorlin et al, in the United States and worldwide. Examples include holoprosencephaly-3 (mutations However, most studies indicate that inherited vari- in the sonic hedgehog homolog gene), several types ation has the greater overall effect on susceptibility. Most of these syndromes are ent, empirical risk tables are based on epidemiological rare, but in aggregate the group has a substantial studies and thus provide only population averages impact on human health. Dentists often have an important role to syndromic families, evidence suggesting a monogenic play in both the quick and accurate identification of dominant or X-linked pattern of transmission can be the syndrome and referral for counseling. The growing list of syndromic clefting, it is also important for dental possible environmental teratogens can also assist in professionals to make referrals for genetic counsel- pregnancy counseling to reduce, but not eliminate, risk ing and to help educate the public about the risks of of having a child with a cleft. Estimates of actual incidence vary, but a reasonable The current standard of care for patients with range would be between 1 in 750-1000 live births for clefts and other craniofacial developmental disor- Whites, with approximately twice this incidence for ders is based on the concept of interdisciplinary Native Americans and Asians, and half this incidence team care, including significant contributions from for African Americans. The Parameters for palate is about twice as common in males as in females, Evaluation and Treatment of Patients with Cleft while the reverse is true for isolated cleft palate. The dental components slight irregularity of the bite to severe difficulty with to the cleft/craniofacial team represent some of the mastication. Abnormal tooth and jaw alignment can most significant contributions to total patient reha- affect speech, and in severe cases an abnormal facial bilitation, including pediatric dental care, orthodon- appearance may affect the psychological well-being of tics, oral and maxillofacial surgery and prosthodon- the individual (Berscheid, 1980). In addition, the dental specialists on the Although a single specific cause of malocclusion cleft/craniofacial team play key roles at almost every may sometimes be apparent––e. This interaction occurs Research efforts to determine optimal ways to in, and has an effect on, the craniofacial skeleton, deliver health services to these patients have been dentition, orofacial neuromusculature, and other hampered by a lack of consensus on minimal stan- soft tissues, including those that border the airway. Current out- sus environmental influences on the etiology of maloc- comes research has traditionally excluded parent clusion, there is evidence of a genetic influence on many participation in defining treatment success or fail- aspects of dental and occlusal variation (Mossey, 1999). Furthermore, evidence for something as basic as the cost-effectiveness of team Estimates of the incidence of malocclusion in the care is currently lacking, in spite of overwhelming United States vary with the criteria used. While prevalence of malocclusion and orthodontic treat- several recent research initiatives such as the ment need in the United States from data in the third Eurocleft project in Europe (Shaw et al, 2001) and National Health and Nutrition Examination Survey the Craniofacial Outcomes Registry in the United (Proffit et al, 1998).
However super levitra 80mg online, it is important to note that each type of technology exhibits a bias towards certain compound classes buy super levitra 80 mg with visa, mostly due to ionization techniques discount 80 mg super levitra with visa, chromatog- raphy and detector capabilities buy generic super levitra canada. Ultracomplex samples contain hundreds of co-eluting compounds that vary in abun- dance by several orders of magnitude. Urinary Proﬁling by Capillary Electrophoresis Metabolomic approaches have become particularly important for discovery of bio- markers in urine. The analytical technology for urinary proﬁling must be efﬁcient, sensitive and offer high resolution. These proﬁles have been visualized using novel advanced pattern recognition tools. The method has been applied in investigation of biomarkers characteristic of alcoholics or Down’s syndrome persons. Lipid Proﬁling Modern medicine has come to rely on a small suite of single biomarkers, such as plasma cholesterol or triglycerides, to assess the risk of certain diseases. However, such single-biomarker assessments overlook the inherent complexity of metabolic disorders involving hundreds of biochemical processes. Assessing the full breadth of lipid metabolism is what drives the ﬁeld of lipomic proﬁling. However, unlike the other “-omics” technologies, in which only a small portion of the genes or proteins is known, lipid metabolic pathways are well characterized. Another limitation of “-omics” technologies is that they produce so many false positive results that it is difﬁcult to be sure that ﬁndings are valid. Metabolomics is not immune to this prob- lem but, when practiced effectively, the technology can reliably produce knowledge to aid in decision making. Focused metabolomics platforms, which restrict their target analytes to those measured well by the technology, can produce data with properties that maximize sensitivity and minimize the false discovery problem. TrueMass® (Lipomic Technologies) analysis produces lipomic proﬁles − comprehensive and quantitative lipid metabolite proﬁles of biological samples. With TrueMass, Lipomics measures hundreds of lipid metabolites from each small quantity of tissue, plasma or serum sample. Because the resulting data are quantitative, TrueMass data can be seam- lessly integrated with pre-existing or future databases. No separation of lipids is required, and the accuracy of identiﬁcation and quantiﬁcation is not compromised, compared to conventional precursor and neutral loss scanning. Role of Metabolomics in Biomarker Identiﬁcation and Pattern Recognition Metabolomics research has increased signiﬁcantly over recent years due to advances in analytical measurement technology and the advances in pattern recognition soft- ware enabling one to visualize changes in levels of hundreds or even thousands of Universal Free E-Book Store 174 7 Role of Metabolomics in Personalized Medicine chemicals simultaneously. Multivariate metabolomic and proteomic data and time- series measurements can be combined to reveal protein-metabolite correlations. Different methods of multivariate statistical analysis can be explored for the inter- pretation of these data. Biomarkers that are responsible for these different biological characteristics can easily be classiﬁed because of the optimized separation using independent compo- nents analysis and an integrated metabolite-protein dataset. Evidently, this kind of analysis depends strongly on the comprehensiveness and accuracy of the proﬁling method, in this case metabolite and protein detection. Assuming that the techniques will improve, more proteins and metabolites can be identiﬁed and accurately quanti- ﬁed, the integrated analysis will have great promise. Validation of Biomarkers in Large-Scale Human Metabolomics Studies A strategy for data processing and biomarker validation has been described in a large metabolomics study that was performed on 600 plasma samples taken at four time points before and after a single intake of a high fat test meal by obese and lean subjects (Bijlsma et al. Such metabolomics studies require a careful ana- lytical and statistical protocol. A method combining several well-established statis- tical methods was developed for processing this large data set in order to detect small differences in metabolic proﬁles in combination with a large biological varia- tion. The strategy included data preprocessing, data analysis, and validation of sta- tistical models. Univariate plots of potential biomarkers were used to obtain insight in up- or down-regulation. Pharmacometabonomics A major factor underlying inter-individual variation in drug effects is variation in metabolic phenotype, which is inﬂuenced not only by genotype but also by environ- mental factors such as nutritional status, the gut microbiota, age, disease and the co- or pre-administration of other drugs. Thus, although genetic variation is clearly important, it seems unlikely that personalized drug therapy will be enabled for a wide range of major diseases using genomic knowledge alone. Metabolite patterns Universal Free E-Book Store Metabonomic Technologies for Toxicology Studies 175 that are characteristic of the individual can be used to diagnose diseases, predict an individual’s future illnesses, and their responses to treatments. The principle of pharmacometabonomics has been demonstrated in humans by showing a clear connection between an individual’s metabolic phenotype, in the form of a predose urinary metabolite proﬁle, and the metabolic fate of a standard dose of the widely used analgesic acetaminophen (Clayton et al. The predose spectra were statistically analyzed in relation to drug metabolite excre- tion to detect predose biomarkers of drug fate and a human-gut microbiome come- tabolite predictor was identiﬁed. Thus, the investigators found that individuals having high predose urinary levels of p-cresol sulfate had low postdose urinary ratios of acetaminophen sulfate to acetaminophen glucuronide. They conclude that, in individuals with high bacterially mediated p-cresol generation, competitive O-sulfonation of p-cresol reduces the effective systemic capacity to sulfonate acet- aminophen. Given that acetaminophen is such a widely used and seemingly well- understood drug, this ﬁnding provides a clear demonstration of the immense potential and power of the pharmacometabonomic approach. However, many other sulfonation reactions are expected to be similarly affected by competition with p-cresol and these ﬁnding also has important implications for certain diseases as well as for the variable responses induced by many different drugs and xenobiotics. It is proposed that assessing the effects of microbiome activity should be an integral part of pharmaceutical development and of personalized health care. Furthermore, gut bacterial populations might be deliberately manipulated to improve drug efﬁ- cacy and to reduce adverse drug reactions. Pharmacometabonomics could be used to preselect volunteers at key stages of the clinical trials. This would enable stratiﬁ- cation of subjects into cohorts, which could minimize the risk of adverse events, or focus on those individuals with a characteristic disease phenotype for assessment of efﬁcacy. Metabonomic Technologies for Toxicology Studies Metabonomics studies demonstrate its potential impact in the drug discovery pro- cess by enabling the incorporation of safety endpoints much earlier in the drug discovery process, reducing the likelihood (and cost) of later stage attrition. Global metabolic proﬁling (metabonomics/metabolomics) has shown particular promise in the area of toxicology and drug development. A metabolic proﬁle need not be a comprehensive survey of composition, nor need it be completely resolved and assigned, although these are all desirable attributes. For the proﬁle to be useful across a range of problems, however, it must be amenable to quantitative interpreta- tion and it should be relatively unbiased in its scope. A further requirement for the Universal Free E-Book Store 176 7 Role of Metabolomics in Personalized Medicine platform used to generate proﬁles is that the analytical variation introduced postcol- lection be less than the typical variation in the normal population of interest, so as not to reduce signiﬁcantly the opportunity to detect treatment/group-related differ- ences. Fulﬁlling this condition is very dependent on the actual system and question in hand and is probably best tested in each new application. In both preclinical screening and mechanistic exploration, metabolic proﬁling can offer rapid, noninvasive toxicological information that is robust and reproduc- ible, with little or no added technical resources to existing studies in drug metabo- lism and toxicity. Extended into the assessment of efﬁcacy and toxicity in the clinic, metabonomics may prove crucial in making personalized therapy and pharmacoge- nomics a reality. The company believes that it is possible to proﬁle metabolic diseases before symptoms appear. Metabonomic testing is important in obesity/metabolic syndromes, in which several metabolic pathways interact to produce symptoms and could be an important guide to select diets and exercise programs tailored to metabolic states. It is considered desirable to establish a human “metabonome” parallel to human genome and proteome but it will be a formidable undertaking requiring analysis of at least half a million people. Some projects are examining metabonomic patterns in series of patients with metabolic syndromes and comparing them with normal peo- ple. Other studies are examining how a person’s unique metabonomic proﬁle can be used as a guide to personalize diet and exercise regimens for obesity. It is now possible to measure hundreds or thousands of metabolites in small samples of biological ﬂuids or tissues. This enables assessment of the metabolic component of nutritional phenotypes and will enable individualized dietary recom- mendations. The relation between diet and metabolomic proﬁles as well as between those proﬁles and health and disease needs to be established. Appropriate technolo- gies should be developed and that metabolic databases are constructed with the right inputs and organization. Moreover, social implications of these advances and plan for their appropriate utilization should be considered. Large-scale human metabolomics studies: a strategy for data (pre-) processing and validation. Pharmacometabonomic identiﬁcation of a signiﬁcant host-microbiome metabolic interaction affecting human drug metabolism.
I. Tjalf. Principia College.Share this