International Sensitivity

The international normalized ratio (INR) is a method to standardize repotting of the prothrombin time, using the formula, INR = (PTpatie t/PTcontroi)ISI, where PT indicates the prothrombin times (for the patient and the laboratory control), and ISI indicates the international sensitivity index, a value that varies, depending upon the thromboplastin reagent and laboratory instrument used to initiate and detect clot formation, respectively. 

ACCP American College of Chest Physicians ISI International Sensitivity Index... 

International Normalized Ratio (INR) The ratio of the patient s clotting time to the clinical laboratory s mean reference value normalized by raising it to the International Sensitivity Index (ISI) power to account for differences in thromboplastin reagents. Therefore, INR = (patient s prothrombin time/laboratory s mean normal prothrombin time)ISI. 

The optimal therapeutic range for oral anticoagulant therapy as determined by prothrombin time is expressed in terms of the international normalized ratio (INR). The INR is the prothrombin time ratio (patient s prothrombin time divided by the mean of the normal prothrombin time) that would have been obtained had a World Health Organization reference thromboplastin preparation been used to determine the prothrombin time. The sensitivity of the various reagents (thromboplastins) used to determine the prothrombin time is related to the international sensitivity... 

It is worth mentioning that the overall sensitivity can be modified by changing both the value of the polarization current I and the amplification value A. As a particular case, when / = 1 fiA and A= 106, the product of I and A is equal to 1, so that the Overall Sensitivity coincides with the Internal Sensitivity divided by R(T). 

The relationship between INR on cotherapy and warfarin alone is dependent on the dose of argatroban and the thromboplastin reagent used. Thromboplastins with higher International Sensitivity Index (ISI) values result in higher INRs on combined therapy of warfarin and argatroban. 

Each of these azides contains an internal sensitizing group. Upon LFP the triplet states of all three azides are observed. However, in the case of 17 and 18, only singlet nitrene derived products are formed. Photolysis of 17 and 18 at 8 K in fluorolube fails to produce persistent triplet EPR spectra. It seems clear that these aroyl nitrenes also have singlet ground states. As mentioned previously, photolysis of 14 does produce a triplet nitrene EPR spectrum. 

The photographic attributes of (S+Au)-sensitization are similar to those of S-sensitization. Both act primarily to increase the sensitivity for surface image formation. Both usually decrease the sensitivity for internal latent image formation in emulsions that show considerable internal sensitivity in their unsensitized form. Bahnmueller (163) and Farnell and Solman (164) observed that, in emulsions of this type, the combined (S+ Au)-sensitization produced a greater increase in surface sensitivity and a greater decrease in internal sensitivity than S-sensitization alone, but sensitization with gold alone increased surface sensitivity without impairing the internal sensitivity (163). 

Ts ao C, Swedlund J, Neofotistos D. Implications of use of low international sensitivity index thromboplastins in prothrombin time testing. Arch Pathol Lab Med 1994 118 1183-7. 

The International Sensitivity Index (ISI) is a measure of the thromboplastin s responsiveness compared with the WHO reference standard. Each thromboplastin reagent manufactured has an ISI valne that should be used to calculate the INR. Although the INR system has a number of potential problems, it is currently the best means available... 

International normalised ratio (INR). The DSTR was adopted by the WHO in 1982 to standardise (using the International Sensitivity Index) oral anticoagulant therapy to take into account the sensitivities of the different thromboplastins used in laboratories across the world. The formula for calculating the INR is as follows ... 

A. Fillinger, B. A. Parkinson, The adsorption behavior of a ruthenium-based sensitizing dye to nanocrystalline Ti02 - coverage effects on the external and internal sensitization quantum yields, J. Electrochem. Soc. 1999, 146(12), 4559-4564. 

Evans FJ, Gilman P (1975) Comparison of the spectral sensitization of surface and internally sensitized core/shell octahedral silver bromide emulsions. Photogr Sci Eng 19 344-351... 

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