Databases retrospective searching

Derwent Information Ltd. Derwent Information Ltd., previously known as Derwent PubHcations Ltd., changed its name in the 1990s to reflect more accurately the fact that its products go far beyond traditional pubHcations. Derwent provides a wide spectmm of information products and services, many of them relating to patents. Derwent also produces important databases (qv) of nonpatent information from the pharmaceutical and agncultural chemical Hterature. These products and services encompass alerting tools for current awareness, systems for retrospective search and retneval, and means for document deHvery and archiving. 

A better way to obtain the information we seek is to use chemical literature databases. Several such databases exist. These resources can be used for retrospective searches of mentions of any given program, vendor, method, or other term. It is also highly fitting to use a computerized technique (database searching) in our study of computational chemistry. 

Retrospective database searching has no influence on the treatment of the patient and is thus free from any inducements to change treatment for the purposes of the study. 

The FOI Online Web site (cited previously) also enables keyword searching of a huge retrospective collection of FDA Warning Letters, as well as FDA Guidance documents. Both of these compilations complement those offered on the FDA web site. Since the database supplier is also a document delivery service, the online file serves as a catalog of materials stored in-house after being obtained through Freedom of Information Act provisions. This means that items not separately listed or readily searchable on the FDA Web site are indexed at FOI Online. For example, the database provides separate... 

In addition to the regular trades and press releases, the database includes content from local, national, and international newspapers, government publications, and market research studies. Users can search by SIC and NAICS codes, company name, trade name, or geographic location. It is updated daily. Retrospective coverage goes back to 1972. 

If the virtual screening process is successful, the bioactive compounds will be enriched in the upper part of this ranked list. Enriched means that there are more active compounds in this part of the list than that one would expect based on the average content of bioactive compounds in the searched database. This enrichment can be determined only in retrospective studies where both the active and the inactive compounds in the database are known The emichment factor is typically used in such studies as a quality criterion for a particular virtual screening approach. Since the emichment factor depends on the chosen subset of the ranked list, it is common to calculate enrichment curves where the cumulated number of hits is plotted against the ranked list of compounds in the search database. In recent years, more and more researchers prefer other types of enrichment plots (e.g., ROC curves). The interested... 

The simplest way to compare the performance of different descriptors is to perform a retrospective study and to count the numbers of true actives found in different virtual screening hit lists of predefined size and compare them with the hit rate in the search database (enrichment). Enrichment factors, however, are not sufficient to assess the scaffold hopping potential of a descriptor or a search method. 

For real retrospective data analyses, such as stability tests, it is often necessary to compare data from different measurement points with each other. For this purpose, the use of electronically stored data is advantageous, because it is very easy to superimpose and compare chromatograms and search within the databases. However, electronic filing systems, for example, file or database formats, provide some challenges regarding the recoverability of the data during the regulatory retention period (see Section 8.2.4). 

High resolution Time-Of-Flight (TOF) MS gives protonated molecular ions of most PAs with very high mass accuracy. This allows the determination of empirical sum formulae and easy searching for PAs using databases from empirical formulae with accurately calculated masses. Although less sensitive than LC-MS/MS methods, spectra are obtained for all ionizable compounds and the raw data can be searched retrospectively. 

Retrospective analysis of incidents is supported by tools that enable the alarm database to be searched for unnecessary duplicate alarms, multiple occurrences of the same alarm, exact timing and sequence of alarms, alarms associated with the same equipment or plant area etc. 

In another retrospective population-based case-control study, data from the National Health Insurance Research Database were scrutinized in a search for patients with heart failure newly treated with digoxin between January 2001 and December 2004 who were hospitalized for digitalis toxicity they were compared with the matched controls for use of clarithromycin [5 ]. Prescription of clarithromycin before the index date was associated with increased risk of hospitalization for digoxin intoxication the relative risks were 4.36 at 7 days (95% Cl = 1.28,15), 5.07 at 14 days (95% Cl = 2.36, 11), and 2.98 at 30 days (95% Cl = 1.59, 5.63). The effect was dose related. 

The literature before 1967 is included retrospectively in the database CAOLD, which, in the meantime, contains 700,000 references to 1.4 million substances, which were mentioned before 1967, and 152.000 references to patents. For this database Chemical Abstracts Service scans bit by bit the Formula Index of the Sixth (1957-1961) and the Seventh (1962-1966) Collective Period. Therefore only substance references are contained in this database with no text information or even abstracts. However, cross-references to patents are marked with P. Using this database you have to consider that the chemical nomenclature in those days was quite different to the names in use today. Therefore an online search in CAOLD should be proceded by a search in the Registry File (Sect. 7.6) and then continued with the appropriate CAS Registry Number in CAOLD. 

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