Structural analysis of oligomeric molecules formed from the reaction products of oleic acid ozonolysis

The products arising from the ozonolysis of oleic acid (cis-9-octadecenoic acid) in solution have been studied using negative ion mode electrospray ionization ion trap mass spectrometry. Oleic acid is an important component of atmospheric organic aerosol and is a key model species in predicting aerosol physical and chemical characteristics. The four predicted reaction products, 1-nonanal, nonanoic acid, 9-oxononanoic acid, and azelaic acid, were all observed in roughly equal yields. In addition to these products a large number of higher molecular weight compounds were detected with m/z ratios of up to 1000 Daltons. Tandem mass spectrometry of these larger ions revealed thatthey represented a complex mixture of linear alpha-acyloxyalkyl hydroperoxides, secondary ozonides, and cyclic diperoxides, formed by reactions between ozonolysis products and Criegee intermediates. These comprise the first directly elucidated structures of large oligomeric species from oleic acid ozonolysis. The degree of oligomerization and hence molecular weight distribution was observed to increase with reaction time in solution.

Comparison and evaluation of Osiris and Sirscan 2000 antimicrobial susceptibility systems in the clinical microbiology laboratory

The Osiris and Sirscan 2000 systems are two semiautomated systems that can be used to read and interpret the results on disk diffusion agar plates. They are both used for determination of susceptibility to antimicrobial agents. The present study compared both systems versus the NCCLS standard method of visual reading with a ruler. Both inpatient and outpatient samples with a total of 315 nonfastidious gram-negative strains were obtained. In total, 3724 organism-antimicrobial agent combinations that fulfilled the NCCLS guidelines for disk diffusion susceptibility testing were evaluated prospectively. The results obtained with both systems in comparison with those obtained by the classical nonautomated means of interpretation were excellent, with correlation coefficients of 0.96 for both systems. The overall agreements for susceptibility interpretation were 96.56 and 96.24% with the Osiris and Sirscan systems, respectively. Very major errors were obtained for 8 (1.07%) and 10 (1.34%) organism-antimicrobial agent combinations with the Osiris and Sirscan systems, respectively. In addition, major errors were obtained for 2 (0.07%) and 6 (0.21%) combinations with the Osiris and Sirscan systems, respectively. Minor errors were obtained for 118 and 124 organism-antimicrobial agent combinations with the Osiris and Sirscan systems, respectively. Overall, both the Osiris system and the Sirscan system are comparable and reliable systems for determination of interpretative categories from the zone diameters of standard disk diffusion test plates.

Streptococcus pneumoniae-infected aneurysm extending from a persistent lobar pneumonia: case report and review of the literature

Presented here is the case of a 63-year-old patient with a Streptococcus pneumoniae-infected aneurysm extending from a persistent lobar pneumonia of the left lung into the thoracic aorta. The patient was successfully treated with surgery and high-dose penicillin, and he remained well at 6-month follow-up. A review of the English-language literature over the past 25 years revealed 22 cases of mycotic or infected aortic aneurysms due to Streptococcus pneumoniae; however, none of these cases resulted in a positive outcome for the patient. The characteristics of these cases are discussed.

Radiosensitization by cytotoxic drugs. The EORTC experience by the Radiotherapy and Lung Cancer Cooperative Groups

A three-arm randomized trial was performed to assess the acute and late toxicity and the impact on survival of the combination high-dose, split-course radiotherapy with 30 mg/m2 cisplatin (cDDP) weekly, with 6 mg/m2 cisplatin daily compared to radiotherapy alone in patients with non-small cell lung cancer (NSCLC). The study started in May 1984 and was closed in May 1989 after 331 patients were randomised. The analysis was performed after a minimum follow-up period of 22 months. Radiotherapy (RT) consisted of 30 Gy, 10 fractions, five fractions a week; then a 3-week split followed by 25 Gy in 10 fractions. Nausea and vomiting were increased for a majority of the patients in the combined treatment arms during treatment. There was no addition of bone marrow suppression, renal dysfunction or esophagitis. Increase of late radiation damage was not observed. Local control (= absence of local progression) was improved for patients treated according to the daily cisplatin arm. This has lead to an improvement in overall survival. There was no effect in time to distant metastasis due to the combined modality. The treatment influence was confirmed in the multivariate analysis.

CONCLUSION

local control and survival can be improved by combining radiotherapy with daily low-dose cisplatin in patients with inoperable NSCLC.

Effects of concomitant cisplatin and radiotherapy on inoperable non-small-cell lung cancer

BACKGROUND AND METHODS

Cisplatin (cis-diamminedichloroplatinum) has been reported to enhance the cell-killing effect of radiation, an effect whose intensity varies with the schedule of administration. We randomly assigned 331 patients with nonmetastatic inoperable non-small-cell lung cancer to one of three treatments: radiotherapy for two weeks (3 Gy given 10 times, in five fractions a week), followed by a three-week rest period and then radiotherapy for two more weeks (2.5 Gy given 10 times, five fractions a week); radiotherapy on the same schedule, combined with 30 mg of cisplatin per square meter of body-surface area, given on the first day of each treatment week; or radiotherapy on the same schedule, combined with 6 mg of cisplatin per square meter, given daily before radiotherapy.

RESULTS

Survival was significantly improved in the radiotherapy-daily-cisplatin group as compared with the radiotherapy group (P = 0.009): survival in the radiotherapy-daily-cisplatin group was 54 percent at one year, 26 percent at two years, and 16 percent at three years, as compared with 46 percent, 13 percent, and 2 percent, respectively, in the radiotherapy group. Survival in the radiotherapy-weekly-cisplatin group was intermediate (44 percent, 19 percent, and 13 percent) and not significantly different from survival in either of the other two groups. The survival benefit of daily combined treatment was due to improved control of local disease (P = 0.003). Survival without local recurrence was 59 percent at one year and 31 percent at two years in the radiotherapy-daily-cisplatin group; 42 percent and 30 percent, respectively, in the radiotherapy-weekly-cisplatin group; and 41 percent and 19 percent, respectively, in the radiotherapy group. Cisplatin induced nausea and vomiting in 86 percent of the patients given it weekly and in 78 percent of those given it daily; these effects were severe in 26 percent and 28 percent, respectively.

CONCLUSIONS

Cisplatin, given daily in combination with the radiotherapy described here to patients with nonmetastatic but inoperable non-small-cell lung cancer, improved rates of survival and control of local disease at the price of substantial side effects.