NAME

UMLS::Interface - Perl interface to the Unified Medical Language System (UMLS)

SYNOPSIS #!/usr/bin/perl

use UMLS::Interface;

$umls = UMLS::Interface->new(); 

die "Unable to create UMLS::Interface object.\n" if(!$umls); 

my $root = $umls->root();

my $term1    = "blood";

my @tList1   = $umls->getConceptList($term1);
my $cui1     = pop @tList1;

if($umls->exists($cui1) == 0) { 
   print "This concept ($cui1) doesn't exist\n";
} else { print "This concept ($cui1) does exist\n"; }

my $term2    = "cell";
my @tList2   = $umls->getConceptList($term2);

my $cui2     = pop @tList2;
my $exists1  = $umls->exists($cui1);
my $exists2  = $umls->exists($cui2);

if($exists1) { print "$term1($cui1) exists in your UMLS view.\n"; }
else         { print "$term1($cui1) does not exist in your UMLS view.\n"; }

if($exists2) { print "$term2($cui2) exists in your UMLS view.\n"; }
else         { print "$term2($cui2) does not exist in your UMLS view.\n"; }
print "\n";

my @cList1   = $umls->getTermList($cui1);
my @cList2   = $umls->getTermList($cui2);

print "The terms associated with $term1 ($cui1):\n";
foreach my $c1 (@cList1) {
   print " => $c1\n";
} print "\n";

print "The terms associated with $term2 ($cui2):\n";

foreach my $c2 (@cList2) {
   print " => $c2\n";
} print "\n";

my $lcs = $umls->findLeastCommonSubsumer($cui1, $cui2);
print "The least common subsumer between $term1 ($cui1) and \n";
print "$term2 ($cui2) is $lcs\n\n";

my @shortestpath = $umls->findShortestPath($cui1, $cui2);
print "The shortest path between $term1 ($cui1) and $term2 ($cui2):\n";
print "  => @shortestpath\n\n";

my $pathstoroot   = $umls->pathsToRoot($cui1);
print "The paths from $term1 ($cui1) and the root:\n";

foreach  $path (@{$pathstoroot}) {
   print "  => $path\n";
} print "\n";

my $mindepth = $umls->findMinimumDepth($cui1);
my $maxdepth = $umls->findMaximumDepth($cui1);
print "The minimum depth of $term1 ($cui1) is $mindepth\n";
print "The maximum depth of $term1 ($cui1) is $maxdepth\n\n";

my @children = $umls->getChildren($cui2); 
print "The child(ren) of $term2 ($cui2) are: @children\n\n";

my @parents = $umls->getParents($cui2);
print "The parent(s) of $term2 ($cui2) are: @parents\n\n";

my @relations = $umls->getRelations($cui2);
print "The relation(s) of $term2 ($cui2) are: @relations\n\n";

my @rel_sab = $umls->getRelationsBetweenCuis($cui1, "C1524024");
print "The relation (source) between $cui1 and $cui2: @rel_sab\n";

my @siblings = $umls->getRelated($cui2, "SIB");
print "The sibling(s) of $term2 ($cui2) are: @siblings\n\n";

my @definitions = $umls->getCuiDef($cui1);
print "The definition(s) of $term1 ($cui1) are:\n";

foreach $def (@definitions) {
   print "  => $def\n"; $i++;
} print "\n";

my @sabs = $umls->getSab($cui1);

print "The sources containing $term1 ($cui1) are: @sabs\n";

print "The semantic type(s) of $term1 ($cui1) and the semantic\n";

print "definition are:\n";
my @sts = $umls->getSt($cui1);

foreach my $st (@sts) {

   my $abr = $umls->getStAbr($st);
   my $string = $umls->getStString($abr);
   my $def    = $umls->getStDef($abr);
   print "  => $string ($abr) : $def\n";

} print "\n";

$umls->removeConfigFiles();

$umls->dropConfigTable();

ABSTRACT

This package provides a Perl interface to the Unified Medical Language System. The package is set up to access pre-specified sources of the UMLS present in a mysql database. The package was essentially created for use with the UMLS::Similarity package for measuring the semantic relatedness of concepts.

INSTALL

To install the module, run the following magic commands:

perl Makefile.PL
make
make test
make install

This will install the module in the standard location. You will, most probably, require root privileges to install in standard system directories. To install in a non-standard directory, specify a prefix during the 'perl Makefile.PL' stage as:

perl Makefile.PL PREFIX=/home/sid

It is possible to modify other parameters during installation. The details of these can be found in the ExtUtils::MakeMaker documentation. However, it is highly recommended not messing around with other parameters, unless you know what you're doing.

DESCRIPTION

This package provides a Perl interface to the Unified Medical Language System (UMLS). The UMLS is a knowledge representation framework encoded designed to support broad scope biomedical research queries. There exists three major sources in the UMLS. The Metathesaurus which is a taxonomy of medical concepts, the Semantic Network which categorizes concepts in the Metathesaurus, and the SPECIALIST Lexicon which contains a list of biomedical and general English terms used in the biomedical domain. The UMLS-Interface package is set up to access the Metathesaurus and the Semantic Network present in a mysql database.

DATABASE SETUP

The interface assumes that the UMLS is present as a mysql database. The name of the database can be passed as configuration options at initialization. However, if the names of the databases are not provided at initialization, then default value is used -- the database for the UMLS is called 'umls'.

The UMLS database must contain six tables: 1. MRREL 2. MRCONSO 3. MRSAB 4. MRDOC 5. MRDEF 6. MRSTY 7. SRDEF

All other tables in the databases will be ignored, and any of these tables missing would raise an error.

A script explaining how to install the UMLS and the mysql database are in the INSTALL file.

INITIALIZING THE MODULE

To create an instance of the interface object, using default values for all configuration options:

use UMLS::Interface;
my $interface = UMLS::Interface->new();

Database connection options can be passed through the my.cnf file. For example: [client] user = <username> password = <password> port = 3306 socket = /tmp/mysql.sock database = umls

Or through the by passing the connection information when first instantiating an instance. For example:

    $umls = UMLS::Interface->new({"driver" => "mysql", 
				  "database" => "$database", 
				  "username" => "$opt_username",  
				  "password" => "$opt_password", 
				  "hostname" => "$hostname", 
				  "socket"   => "$socket"}); 

  'driver'       -> Default value 'mysql'. This option specifies the Perl 
                    DBD driver that should be used to access the
                    database. This implies that the some other DBMS
                    system (such as PostgresSQL) could also be used,
                    as long as there exist Perl DBD drivers to
                    access the database.
  'umls'         -> Default value 'umls'. This option specifies the name
                    of the UMLS database.
  'hostname'     -> Default value 'localhost'. The name or the IP address
                    of the machine on which the database server is
                    running.
  'socket'       -> Default value '/tmp/mysql.sock'. The socket on which 
                    the database server is using.
  'port'         -> The port number on which the database server accepts
                    connections.
  'username'     -> Username to use to connect to the database server. If
                    not provided, the module attempts to connect as an
                    anonymous user.
  'password'     -> Password for access to the database server. If not
                    provided, the module attempts to access the server
                    without a password.

More information is provided in the INSTALL file Stage 5 Step D (search for 'Step D' and you will find it).

PARAMETERS

You can also pass other parameters which controls the functionality of the Interface.pm module.

    $umls = UMLS::Interface->new({"forcerun"      => "1",
				  "realtime"      => "1",
				  "cuilist"       => "file",  
				  "verbose"       => "1", 
                                  "debugpath"     => "file", 
                                  "icpropagation" => "file", 
                                  "icfrequency"   => "file"});

  'forcerun'     -> This parameter will bypass any command prompts such 
                    as asking if you would like to continue with the index 
                    creation. 

  'realtime'     -> This parameter will not create a database of path 
                    information (what we refer to as the index) but obtain
                    the path information about a concept on the fly

  'cuilist'      -> This parameter contains a file containing a list 
                    of CUIs in which the path information should be 
                    store for - if the CUI isn't on the list the path 
                    information for that CUI will not be stored

  'verbose'      -> This parameter will print out the table information 
                    to a config file in the UMLSINTERFACECONFIG directory

  'debugpath'    -> This prints out the path information to a file during
                    any of the realtime runs

  'icpropagation'-> This parameter contains a file consisting of the  
                    information content (IC) of a list of CUIs. This 
                    file can be created using the program called: 
                    create-propagation-file.pl in the UMLS-Similarity 
                    package.
  'icfrequency'  -> This parameter contains a file consisting of frequency
                    counts of a CUIs. Then the information content is 
                    created on the fly (in realtime). 

CONFIGURATION FILE

There exist a configuration files to specify which source and what relations are to be used. The default source is the Medical Subject Heading (MSH) vocabulary and the default relations are the PAR/CHD relation.

'config' -> File containing the source and relation parameters

The configuration file can be passed through the instantiation of the UMLS-Interface. Similar to passing the connection options. For example:

    $umls = UMLS::Interface->new({"driver"      => "mysql", 
				  "database"    => $database, 
				  "username"    => $opt_username,  
				  "password"    => $opt_password, 
				  "hostname"    => $hostname, 
				  "socket"      => $socket,
                                  "config"      => $configfile});

    or

    $umls = UMLS::Interface->new({"config" => $configfile});

The format of the configuration file is as follows:

SAB :: <include|exclude> <source1, source2, ... sourceN>

REL :: <include|exclude> <relation1, relation2, ... relationN>

RELA :: <include|exclude> <rela1, rela2, ... relaN>

SABDEF :: <include|exclude> <source1, source2, ... sourceN>

RELDEF :: <include|exclude> <relation1, relation2, ... relationN>

The SAB, REL and RELA are for specifing what sources and relations should be used when traversing the UMLS. For example, if we wanted to use the MSH vocabulary with only the RB/RN relations that have been identified as 'isa' RELAs, then the configuration file would be:

SAB :: include MSH REL :: include RB, RN RELA :: include inverse_isa, isa

if we did not care what type of RELA the RB/RN relations were the configuration would be:

SAB :: include MSH REL :: include RB, RN

if we wanted to use MSH and use any relation except for PAR/CHD, the configuration would be:

SAB :: include MSH REL :: exclude PAR, CHD

The SABDEF and RELDEF are for obtaining a definition or extended definition of the CUI. SABDEF signifies which sources to extract the definition from. For example,

SABDEF :: include SNOMEDCT

would only return definitions that exist in the SNOMEDCT source. where as:

SABDEF :: exclude SNOMEDCT

would use the definitions from the entire UMLS except for SNOMEDCT. The default, if you didn't specify SABDEF at all in the configuration file, would use the entire UMLS.

The RELDEF is from the extended definition. It signifies which relations should be included when creating the extended definition of a given CUI. For example,

RELDEF :: include TERM, CUI, PAR, CHD, RB, RN

This would include in the definition the terms associated with the CUI, the CUI's definition and the definitions of the concepts related to the CUI through either a PAR, CHD, RB or RN relation. Similarly, using the exclude as in:

RELDEF :: exclude TERM, CUI, PAR, CHD, RB, RN

would use all of the relations except for the one's specified. If RELDEF is not specified the default uses all of the relations which consist of: TERM, CUI, PAR, CHD, RB, RN, RO, SYN, and SIB.

I know that TERM and CUI are not 'relations' but we needed a way to specify them and this seem to make the most sense at the time.

An example of the configuration file can be seen in the samples/ directory.

REFERENCING

If you write a paper that has used UMLS-Interface in some way, we'd 
certainly be grateful if you sent us a copy and referenced UMLS-Interface. 
We have a published paper that provides a suitable reference:

@inproceedings{McInnesPP09,
   title={{UMLS-Interface and UMLS-Similarity : Open Source 
           Software for Measuring Paths and Semantic Similarity}}, 
   author={McInnes, B.T. and Pedersen, T. and Pakhomov, S.V.}, 
   booktitle={Proceedings of the American Medical Informatics 
              Association (AMIA) Symposium},
   year={2009}, 
   month={November}, 
   address={San Fransico, CA}
}

This paper is also found in
<http://www-users.cs.umn.edu/~bthomson/publications/pubs.html>
or
<http://www.d.umn.edu/~tpederse/Pubs/amia09.pdf>

SEE ALSO

http://tech.groups.yahoo.com/group/umls-similarity/

http://search.cpan.org/dist/UMLS-Similarity/

AUTHOR

Bridget T McInnes <bthomson@cs.umn.edu> Ted Pedersen <tpederse@d.umn.edu>

COPYRIGHT

Copyright (c) 2007-2009
Bridget T. McInnes, University of Minnesota
bthomson at cs.umn.edu

Ted Pedersen, University of Minnesota Duluth
tpederse at d.umn.edu

Siddharth Patwardhan, University of Utah, Salt Lake City
sidd at cs.utah.edu

Serguei Pakhomov, University of Minnesota Twin Cities
pakh0002 at umn.edu

Ying Liu, University of Minnesota
liux0935 at umn.edu

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to

The Free Software Foundation, Inc.,
59 Temple Place - Suite 330,
Boston, MA  02111-1307, USA.