J. Liu

 Macrolide antibiotics are widely used for treatment of community-acquired infectious diseases, but its side effects have not been thoroughly investigated, especially on the intestinal tract. Erythromycin, roxithromycin and azithromycin are macrolide antibiotics sharing similar chemical structure and their side effects on intestinal microflora of BALB/c mice were tested in this study. The bacterial composition of microflora was determined by 16S rRNA gene analysis conducted by polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE). The dominant bands were selected and sequenced to determine each individual bacteria. The total amount of 16S rRNA gene was reduced after macrolide antibiotics were administrated, and the specific pattern of bacterial composition was identified from each drug treatment. Bacteroides sp. and Clostridium butyricum str. were dominant intestinal organisms in all three drug-treated mice. This study reveals a significant change of bacterial composition of microflora on the tested mice for macrolide antibiotics.   Key words: Macrolide antibiotics, side effects, intestinal microflora, polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). 

18173 Background: There has been increasing interest in the use of weekly administration of docetaxel as a way of reducing its hemotologic toxicity. Weekly docetaxel plus cisplatin has also shown promising efficacy and well tolerability for first-line treatment of advanced or metastatic NSCLC in our previous phase I study (2002 ASCO, abstract No 2744). We conducted this phase II trial to further evaluate this regimen’s efficacy and toxicity. Methods: Patients with histologically confirmed stage IIIB or IV NSCLC were treated with docetaxel (35 mg/m 2 , 30 min. iv. infusion) on days 1, 8, 15 and cisplatin (75 mg/m 2 , 30 min. iv. infusion) on day 1 repeated every 4 weeks for up to 6 cycles. Pts received oral dexamethasone 7.5 mg twice daily from the day before chemotherapy and consecutive two days thereafter. The primary endpoint of this phase II study is efficacy of the regimen. Results: A total of 83 patients were enrolled from July 2002 to June 2004, 75 patients were evaluable for response and 83 for safety. Median age was 55 years (range 29–70 years); and 69.9% were male; adenocarcinoma/squamous cell carcinoma/others (65/12/6); stage IIIB /IV( 47/36); ECOG PS 0/1(52/31). Median number of chemotherapy cycles was 3(1–5). One CR (complete response) and 22 PR (partial response) were achieved with an ORR of 30.7% in the evaluable patients. The 1-year survival was 48.6% with a median survival of 10.7 months (range: 3–34 months). Neutropenia was the most common adverse event, though most were mild; Grade III/IV toxicities per patient were: Neutropenia (15.6%), asthenia (11%), skin/nail toxicity (10.8%) and vomiting (9.6%). Febrile neutropenia was not observed. Conclusions: In the present study, the combination of weekly administration docetaxel combining with cisplatin appears well tolerated with very low frequency of severe hematologic toxicity and similarly efficacious as 3-weekly docetaxel in NSCLC pts. No significant financial relationships to disclose.