[R] How to remove square brackets, etc. from address strings?

[Sabina Arndt]

Hello r-help members,

the solutions which Sarah Goslee and arun sent to me in such a prompt 
and helpful manner work well with the examples I cut from the data.frame 
I'm analyzing. Thank you very much for that!
I incorporated them into my R-script and discovered that it still 
doesn't work properly, unfortunately. I have no idea why that's the case.
You see, I want to extract country names from the contents of 
tab-delimited text files. This is an example of the data I'm using: 
http://pastebin.com/mYZNDXg6
This is the script I'm using to import the data: 
http://pastebin.com/Z10UUH3z (It requires the text files to be in a 
folder which doesn't contain any other .txt files.)
This is the script I'm using to extract the country names: 
http://pastebin.com/G37fuPba
This is the string that's in the relevant field of the first record I'm 
working on:

[Engel, Kathrin M. Y.; Schroeck, Kristin; Schoeneberg, Torsten; Schulz, 
Angela] Univ Leipzig, Fac Med, Inst Biochem, Leipzig, Germany; [Teupser, 
Daniel; Holdt, Lesca Miriam; Thiery, Joachim] Univ Leipzig, Fac Med, 
Inst Lab Med Clin Chem & Mol Diagnost, Leipzig, Germany; [Toenjes, Anke; 
Kern, Matthias; Blueher, Matthias; Stumvoll, Michael] Univ Leipzig, Fac 
Med, Dept Internal Med, Leipzig, Germany; [Dietrich, Kerstin; Kovacs, 
Peter] Univ Leipzig, Fac Med, Interdisciplinary Ctr Clin Res, Leipzig, 
Germany; [Kruegel, Ute] Univ Leipzig, Fac Med, Rudolf Boehm Inst 
Pharmacol & Toxicol, Leipzig, Germany; [Scheidt, Holger A.; Schiller, 
Juergen; Huster, Daniel] Univ Leipzig, Fac Med, Inst Med Phys & Biophys, 
Leipzig, Germany; [Brockmann, Gudrun A.] Humboldt Univ, Inst Anim Sci, 
D-10099 Berlin, Germany; [Augustin, Martin] Ingenium Pharmaceut AG, 
Martinsried, Germany

This is the incorrect result my extraction script gives me for the first 
record:

 > C1s[1]
  [1] "[ENGEL,  KATHRIN M. Y." "KRISTIN"                "TORSTEN"
  [4] "GERMANY"                "DANIEL"                 "LESCA MIRIAM"
  [7] "GERMANY"                "ANKE"                   "MATTHIAS"
[10] "MATTHIAS"               "GERMANY"                "KERSTIN"
[13] "GERMANY"                "GERMANY"                "[SCHEIDT,  
HOLGER A."
[16] "JUERGEN"                "GERMANY"                "HUMBOLDT"
[19] "GERMANY"

For some reason the first and sixth pair of the eight square brackets 
are not removed ... Do you understand why?
Instead I'd like to get this result, though:

 > C1s[1]
  [1] "GERMANY"        "GERMANY"        "GERMANY"
  [4] "GERMANY"        "GERMANY"        "GERMANY"
  [7] "HUMBOLDT"        "GERMANY"

What am I doing wrong? What are the errors in my R-script?
Would anybody be so kind as to take a look and help me out, please?
Thank you very much in advance!

Faithfully yours,

Sabina Arndt