Data Monitoring Committees in the Southwest Oncology Group comprise the study leadership and the leadership of the Group, augmented by some outside representation. The early stopping guidelines used by these committees are explicit in each protocol, and can be characterized as specifying a few interim analyses at conservative statistical levels. We describe our ten years of experience with this system, and give examples of different trials which have stopped either for positive or negative results.

Bias↗

PubMedDate not supplied

Chlorostyrenes in fish and sediment samples from the river Elbe.

Chlorinated styrenes were identified in fish (bream) and sediment samples from the river Elbe. Four hexachlorostyrenes, four heptachlorostyrenes (concentrations in fish 1-10 ng/g wet weight) and octachlorostyrene (10-45 ng/g wet weight) were analysed. The gas chromatographic retention times and the electron impact (EI) mass spectra of the respective hepta- and hexachloro congeners found in the environment as well as those of some synthesised compounds are presented and discussed. The comparison of the chromatograms from the samples in the upper part of the river with those from the estuary revealed a possible difference in the pattern of chlorostyrenes.

Animals↗

PubMedDate not supplied

Analysis of flame retarded polymers and recycling materials.

Recycling activities on polymeric materials are increasing and becoming more and more important in recent years. For polymers containing no flame retardants, suitable recycling strategies already exist. In order to investigate the recyclability of flame retarded polymers that contain brominated flame retardants, a number of samples were analysed as received from a recycling company. Following the identification and sorting of the samples according to type of polymers and flame retardants, material recycling was tested for the flame retarded polymers identified to occur most frequently. The reactivity of the flame retardants during the recycling procedure was studied by analysing for brominated dioxins and furans. The results demonstrate that flame retarded polymers can be recycled under certain experimental conditions.

Bromine↗

PubMedDate not supplied

Peritonsillar abscess: recurrence rate and the indication for tonsillectomy.

Two hundred ninety patients treated for peritonsillar abscess (PTA) between 1970 and 1982 were reviewed. The patients were divided into those with a history of recurrent tonsillitis prior to developing PTA (72 patients, 25%), and those without (218 patients, 75%). The patients in the first group had four times more recurrences than those in the second group (40% versus 9.6%). Patients older than 40 years were found to have a lower incidence of throat infections than younger patients, and no PTA recurrences were observed. Neither subsequent tonsillitis nor recurrent PTA was observed among 72 patients (25%) who underwent tonsillectomy 6 to 12 weeks after PTA. The pre-PTA history was found to be a dominant factor in determining the need for tonsillectomy. In patients who suffered from recurrent tonsillitis prior to PTA, tonsillectomy is recommended. In those with a single episode of PTA and no history of tonsillitis, tonsillectomy is not indicated.

Female↗