Sensitive diagnostic tests

Assay of bile acids was an essential tool for the early investigation of the enterohepatic circulation, and proved a focus of attention with the belief that serum bile-acid concentrations would provide a sensitive diagnostic test for liver disease. There are three fundamental assay types, based on enzymatic oxidation of a hydroxyl with linked NAD reduction, chromatographic separations and quantitation, encompassing both gas-liquid and high-performance liquid chromatography, and radioimmunoassay assays. 

Probably the most sensitive diagnostic test of whether or not photolysis of a complex proceeds through an ubiquitous intermediate consists in determining the extent to which copresent reaction modes show different wave length dependencies. This type of test was available for Co (111) systems the problem has been to find suitable Cr(III) systems. Following a report that Co(en)2(H20)2+8 photoisomerized (10), it occurred to us that the analogous Cr(III) species might provide an answer. 

Based on rFC, a modern and yet simple, rapid, specific and sensitive diagnostic test for endotoxin has been developed (Ding and Ho, 2001). rFC is a proenzyme until it encounters trace levels of endotoxin where it unequivocally exhibits full enzymatic activity, hence, acting as a very sensitive and specific biosensor for endotoxin. The resulting activated rFC acts as a catalyst to hydrolyse a synthetic substrate to form a quantifiable product, which measures the level of endotoxin. A fhiorimetric assay... 

The exchange results are, therefore, a sensitive diagnostic test of the degree of strain in olefins, and the as yet unknown tricyclodecene (lib in Fig. 9) with a... 

The facile oxidation of hydroxylamine and its derivatives with periodate has led to the suggestion that the method be used as a sensitive diagnostic test for the presence of the secondary hydroxamic acid link (43). The amM of the alkane dimers at 2670 A is close to 10, i. e., about ten times the absorbancy of ferric monohydroxamate at 5100 A. It should be noted that other attempts to increase the sensitivity of hy-droxamate determination have taken advantage of the relative alkali... 

Jiang Y, Metz CE, Nishikawa RM (1996) An ROC partial area index for highly sensitive diagnostic tests. Radiology 201 745-750... 

We can assume, that the residual iodine deficiency could be eliminated in Austria by increasing salt iodization as in Switzerland Results show, that the increase of iodine content in salt indeed is adequate to prevent iodine deficiency disorders. There was some anxiety, however, that the increased iodine intake would provoke a higher rate of thyrotoxicosis and autoimmime thyroiditis Our figures show that "latent hyperthyroidism" as well as "latent hypothyroidism" and "Hashimoto s Disease" increased since 1986, but these figures can partly be explained by more sensitive diagnostic tests In... 

Turbidimetric Agglutination Immunoassays. Agglutination—precipitation immunoassays were among the first practical appHcations of the antigen—antibody reaction in diagnostic tests. These assays are not as widely used in the 1990s as EIA and FIA because they are either not quantitative enough or lack the sensitivity limits of RIA, EIA, and EIA. 

Reactions not mediated by IgE but produced by a pharmacologic reaction predominantly by the NSAID inhibitors COX-1 and -2 which can cause respiratory, skin or both types of reaction or severe anaphylaxis. These are the most frequent types of reaction. To date, only BAT has been validated as an in vitro diagnostic test with contrasted usefulness. In the best argued study [32], sensitivity of the test... 

Even though stool examination for ova and parasites has remained the major means of diagnosis, other diagnostic tests include enzyme-linked immunosorbent assay (ELISA), which is considered to be between 85% to 98% sensitive and almost 100% specific (ProSpecT, Giardia Microplate Assay, Remel, Lenexa, KS). 

A new tumor marker is evaluated using the same criteria used for many diagnostic tests (i.e., sensitivity, specificity, and accuracy). The diagnostic sensitivity and specificity are best represented by a receiver operating characteristic (ROC) curve. The ROC curve is constructed with the true-positive rate versus false-positive rate at various decision levels. As a test improves in its diagnostic performance, it shifts upward and to the left as the true-positive rate increases and the false-positive rate decreases. 

Endoscopic retrograde cholangiopancreatography is the most sensitive and specific diagnostic test, but it is reserved for patients in whom the diagnosis cannot be established by imaging techniques because of the potential for complications. 

Although culture of infected fluids is not the most sensitive of diagnostic tests for gonorrhea, it is still the diagnostic test of choice because of the high specificity. 

However, in some instances (due to lack of information on exposure, a small number of subjects, concomitant exposure to other substances, local or regional differences in patient referral, etc.) there may be a significant level of uncertainty associated with human data. Moreover, diagnostic tests are carried out to see if an individual is sensitized to a specific agent, and not to determine whether the agent can cause sensitization. 

In addition, abnormalities have been reported in depression, alcoholism, Alzheimer s disease, and multi-infarct dementia. It is important to note that these are statistical findings in the psychiatric research setting, and CT is not sufficiently sensitive or specific to be used as a routine diagnostic test. 

The multivalency of peptide dendrimers has also been used to increase the binding avidity of antigens to antibodies in various immunological assays and diagnostic tests. 27,43,47,48,55-59 Examples in the literature have been reported where the MAP format increases the binding avidity and sensitivity, in some cases >100000 fold. In addition to immunology, MAP types of dendrimers have found applications in areas such as inhibitors, 44,45,51,60,61 artificial proteins, 62 affinity purification, 63 and intracellular transportation, 41 as well as in drug discovery. 53 ... 

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