Search

Objective. Evaluation of the sensitivity and specificity of fine needle aspiration of retroperitoneal masses and lymph nodes in gynecologic oncology. Methods. Retrospective study of 101 punctures administered to 84 patients aged 23–86 years. The method's sensitivity and specificity were evaluated by clinical follow-up. Results. A satisfactory sampling was obtained in 89.1% of punctures, and a cytological diagnosis was made in 88.1%. The size of the lymph nodes punctured was less than 14 mm in 46.5%. This test has a sensitivity of 87.5%, specificity of 88.9%, positive predictive value of 98%, negative predictive value of 53.3%, and accuracy of 87.7%. Four patients presented complications: pain (2), hematoma (1), and right ureteral perforation (1). Conclusions. The fine needle aspiration technique has excellent positive predictive value and low morbidity. As a method of visualization, CT-scan, in combination with lymphography, allows the location of small lesions and the definition of their internal structures. The weak negative predictive value of fine needle aspiration might be correctible by laparoscopy-directed biopsy, and its potential is clearly ensured by the development of techniques for locating sentinel lymph nodes.

A new portable photoacoustic and fluorescence photometer has been built. The instrument is especially made for field measurements but can also be used indoors. This new instrument has many advantages. It can measure the photosynthetic O2 evolution and energy storage, and the vitality index in the same sample. The system is very compact, which makes it easy to transport. A small electrical generator satisfies the 110 V power requirement for field applications. All manipulations are computer controlled including the data acquisition and treatment. The photoacoustic signal‐to‐noise ratio for carbon black is the same under field conditions as in the laboratory (∼2×104) at 130 Hz. Results obtained on declining sugar maple trees in the field are presented. The combination of photoacoustic and fluorescence measurements in one instrument represents a very powerful tool in photosynthesis research.

Photoacoustic spectroscopy was used to monitor acid damage to photosynthesis by measuring photosynthetic O2 evolution in leaves from com and sugar maple plantlets. For 2 months the seedlings were treated with simulated acid rain either by spraying the leaves or by watering the soil at different pH levels. The results indicated a decline of photosynthetic oxygen evolution as the pH of the foliar application of simulated acid rain decreased. The reduced photosynthetic activity was sometimes followed by depigmentation (below pH 3.5). For plantlets treated by watering the soil with an acid mixture, the results showed an increase in the growth rate at higher acidity levels without effect on the photosynthetic activity. All corn seedlings from seeds that germinated in media of different pH levels showed the same photosynthetic activity regardless of the pH, as measured by photoacoustic spectroscopy, but the growth rate was higher at lower pH values than at higher pH values. These results clearly indicate the importance of acid damage to photosynthesis at the foliar level, and the ability of photoacoustic spectroscopy to assess forest decline in its early stages. Key words: photoacoustic spectroscopy, photosynthesis, corn, maple, acid rain, oxygen evolution.