Takafumi Ogura

Establishment of human squamous carcinoma cell lines highly and minimally sensitive to bleomycin and analysis of factors involved in the sensitivity

Human squamous carcinoma cell lines that were highly and minimally sensitive to bleomycin were established from clinical specimens and designated as SCCKN and SCCTF, respectively. Although these cell lines showed a similar growth doubling time in vitro, SCCTF was approximately ten times less sensitive to bleomycin than SCCKN. The bleomycin high and low sensitivities were stable even at the 70‐cell passage level in vitro. In addition, nude mouse tumors produced by SCCTF were less sensitive to bleomycin than those produced by SCCKN, and the ratio of the mean tumor weight in bleomycin‐treated mice to that in control mice was 89.2% in SCCTF and 18.8% in SCCKN. As compared with SCCKN, SCCTF also was less sensitive to peplomycin (5‐fold), mitomycin C (2.3‐fold), cisdiammine dichloroplatinum (2.5‐fold), and vincristine (6.5‐fold). Analyses of low bleomycin sensitivity showed that SCCTF had an approximately 20% decreased cellular accumulation and retention of bleomycin, 1.2‐fold increase of bleomycin hydrolase activity, elevated DNA repair activity, and increased poly(adeno‐sine diphosphate‐ribose) polymerase activity as compared with SCCKN.

Induction chemotherapy is Associated with an increase in the incidence of locoregional recurrence in patients with carcinoma of the oral cavity

This study was conducted to determine long term survival rates and the pattern of failure in patients with carcinoma of the oral cavity treated with induction chemotherapy or preoperative radiotherapy followed by surgery.

Prevention of malodor from intraoral gauze tamponade with the topical use of clindamycin

Azulene ointment with a small dose of clindamycin was used topically in eight patients with maxillary cancer with the intent to inhibit the malodor that originates from a gauze tamponade applied to the postoperative maxillary bony defect. The malodor was either markedly decreased or eliminated in all cases. Concurrent with the decrease or elimination of the malodor, anaerobic microorganisms such as Bacteroides and Peptostreptococcus, which are considered to be involved in the generation of malodor, also became undetectable.