Adsorptive separation of fructose and glucose from an agroindustrial waste of cashew industry.

Nearly all agroindustrial wastes have appreciable sugar content including cashew apples (Anacardium occidentale, L.), which are an important sub-utilized biomass source in Northeastern Brazil. Adsorption in fixed bed, both in batch and continuous modes, is a low-cost separation technique, which has been widely used in the concentration, separation and purification of bioproducts, such as sugars. The present work is an experimental study aimed at measuring responses in fixed bed, needed for design purposes. Two commercial ion-exchange resins were studied: DOWEX Monosphere 99/Ca and DIAION UBK555. The adsorbents showed linear isotherms for both sugars with marked selectivity for fructose (2.2 for DOWEX and 1.5 for DIAION). A mathematical model was used to estimate kinetic parameters and predict breakthrough behaviour of binary solutions and complex feeds. The kinetics of mass transfer was well described by a linear driving force approximation (LDF) and estimated kinetic constants were around 1 min(-1). The results indicate that the use of independent experiments with synthetic monocomponent solutions leads to reliable parameters, and the model is capable to foresee reasonably well the breakthrough curve of the sugars present in the juice, under different purification conditions. The use of complex feeds led to overshoot behaviour, possibly due to the irreversible adsorption of oligosaccharides.

Tumor-associated angiogenesis in prostate cancer.

All solid tumors require the induction of new blood vessels to grow. To begin to study this phenomenon in prostate cancer, we investigated the intensity of tumor associated angiogenesis in prostate non malignant and malignant tissue. Angiogenesis was measured by quantitating microvessels in a total of 67 patients: 23 non malignant biopsy specimens, and 34 malignant specimens from patients who had undergone prostatectomy. Angiogenic activity in prostatic cancer (prostatectomy) tissue (utilizing Factor VIII staining) was then correlated with pathological staging (Whitmore-Jewitt). Overall there appeared to be a trend of increasing microvessel count (MVC) from benign through the advancing stages of prostate cancer. Based on mean microvessel counts we were able to distinguish stage D from all other pathological stages (p = 0.004 between stages C and D). There was, however, no statistically significant difference between stage B and C. We conclude that tumor associated angiogenesis in prostate cancer may have both clinical and pathological significance in prostate cancer.