No abstract

Total thyroidectomy using the harmonic scalpel was the fastest procedure because it was bloodless, and hemostasis and sectioning were controlled with a single instrument; it was, therefore, the most inexpensive procedure because of the reduction of operative time and staff cost. The operative safety was similar for all three procedures. In our series, the harmonic scalpel and the LVSS caused less pain than the conventional hemostasis.

X-Ray absorption spectroscopies, EXAFS (extended X-ray absorption fine structure) and XAN ES (X-ray absorption near-edge structure), were used for probing the structural and chemical environment of vanadium in two different asphaltenic fractions of a Boscan crude oil. Although the level of porphyrins detectable by u.v.-visible spectrophotometry was substantially reduced (i.8. < 15% from the 4 000 p.p.m. of metal) due to successive solvent extractions, the EXAFS spectra of these fractions were still largely dominated by the typical pattern of vanadyl porphyrins, whereas the intense prepeak observed in the XANES spectra also clearly supported the presence of quite large amounts of porphyrins in these fractions. We thus suggest that the u.v.-visible spectrophotometric analyses tend systematically to underestimate the porphyrinic content in these heavy fractions, probably due to some hardly detectable microheterogeneity of the test solutions. E.s.r. spectra are produced which clearly support these various conclusions. Much more elaborate separation procedures are required in order to isolate and identify any ' non-porphyrinic vanadium fraction ' from Boscan crudes.

Surgery for large vestibular schwannomas should have a 0% mortality rate and low morbidity. Otoneurosurgical collaboration, with a preference for the translabyrinthine approach, with surgery undertaken in several phases if need be, provides maximum safety and good functional results as well as an acceptable residual tumor rate.

We performed a prospective study to assess the value of positron emission tomography (PET) with 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) in the prediction of local control in irradiated head and neck squamous cell carcinomas (HNSCCs). Forty-two patients with irradiated HNSCCs underwent 49 FDG-PET scans between 3 and 6 months after the end of radiotherapy. The mean follow-up time after the first FDG-PET scan was 17 months. The result of the FDG-PET scan was true-positive in 6 patients, false-positive in 7 patients, and true-negative in 29 patients. The sensitivity, specificity, positive predictive value, and negative predictive value of FDG-PET scanning were 100%, 81%, 46%, and 100%, respectively. We conclude that FDG-PET scanning is useful for prediction of therapy outcome in irradiated HNSCCs. No biopsy is needed for at least 1 year if an FDG-PET scan is negative. If the scan is positive and the biopsy is negative, decreased FDG uptake measured in a follow-up scan indicates that a local recurrence is unlikely.