Document 3320
 DOCN  M94A3320
 TI    Delay of emergence of ddI resistant specific mutation after long term
       therapy.
 DT    9412
 AU    Kondo M; Saito T; Hayashi T; Ito A; Nagao T; Oka S; Imai M; Kanagawa
       Prefectural Institute of Health, Japan.
 SO    Int Conf AIDS. 1994 Aug 7-12;10(1):103 (abstract no. PA0031). Unique
       Identifier : AIDSLINE ICA10/94369255
 AB    OBJECTIVES: To study emergence of drug resistance specific mutation
       after ddI therapy and to study the effect of AZT therapy before ddI
       therapy on the emergence of the mutation. METHODS: HIV-1 strains were
       isolated from a patient treated with ddI and from patients switched from
       AZT to ddI. The RT gene of HIV-1 isolates were amplified by PCR and
       cloned to M13 vector. Five amino acid mutations in RT gene (Asp67,
       Lys70, Leu74, Thr215, Lys219) associated with resistance to AZT or ddI
       were analyzed. RESULTS: The ddI resistance specific mutation
       (Leu74-->Val) was detected after 6 months from a patient A. But the same
       mutation was not detected after more than 12 months from patients B and
       C who were treated with ddI after long-term therapy with AZT.
       CONCLUSIONS: These results suggest that long term therapy with AZT prior
       to ddI therapy may delay the time of emergence of ddI resistance
       specific mutation in patients treated with ddI.
 DE    Amino Acid Sequence  Case Report  Cloning, Molecular
       Didanosine/*THERAPEUTIC USE  Drug Resistance, Microbial/GENETICS  Genes,
       Viral  Human  HIV Infections/*DRUG THERAPY/*MICROBIOLOGY  HIV-1/*DRUG
       EFFECTS/*GENETICS/ISOLATION & PURIF  *Point Mutation  Polymerase Chain
       Reaction  Reverse Transcriptase/GENETICS  Time Factors
       Zidovudine/THERAPEUTIC USE  MEETING ABSTRACT

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