PASS Approach

The computer program PASS was designed to predict many kinds of biological activity simultaneously based on the structural formulae of chemical compounds. Thus, PASS may estimate the biological activity profiles for virtual molecules, prior to their chemical synthesis and biological testing. 

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Finally, we may wish to consider a multi-pass approach whereby the search region for each unknown parameter is determined by the maximum change of the parameter during the last pass (Luus, 1998). 

A good first pass approach in cases where a compound will not crystallize from a single solvent is to find a solvent in which the compound of interest is relatively soluble and a solvent miscible in the first in which the compound is not soluble (Table 1.10). Dissolve the compound in a minimum amount of the first solvent near the lower of the two boiling points, and then slowly add a second solvent, in which the compound is not soluble, until the solution becomes cloudy. If the antisolvent has a much lower boiling point than the solvent, allow the solution to cool slowly with stirring and add seeds periodically until the solids persist. 

The dynamic first pass approach to CTP measnrement involves the IV administration of an intravascnlar contrast agent, which is tracked with serial imaging dnring its first circnlation throngh the brain tissne capillary bed. The main assnmption of dynamic first pass contrast-enhanced CTP models is that the perfnsion tracer is not diffnsible, neither metabolized nor absorbed by the tissue through which it traverses. This is certainly the case in a healthy hnman brain, however, breakdown of the blood-brain barrier (BBB) in infection, inflammation, or tnmor adds an additional level of complexity. When extensive BBB breakdown exists, leakage of... 

D PASS approach was extensively exploited by Potrzebowski group in the course of investigation of the structural and dynamical properties of the signal sequences of the deltorphin and dermorphin—naturally occurring opioid peptides. This experiment was applied for the structure and dynamics elucidation of Tyr-D-Ala-Phe [92] and investigation the influence of hydratation on the changes in the dynamical properties of the Tyr-L-Ala-Phe tripeptides [93]. 

Efficient programming practices demand effective programming environments that incorporate a set of sophisticated tools to support the steps listed above. A partial list of the desired tools based on a message-passing approach might include these ... 

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