Ecosystem service valuation method through grey water footprint in partially-monitored subtropical watersheds.

The valuation of ecosystem services of pollution regulation in basins with partial monitoring does not have only one consolidated methodology which can be applied in all countries, biomes and across spatio-temporal scales. While different metrics can incorporate elements of uncertainty for decision makers, changes in land use, climate and sectoral demands in basins increase the need for the efficiency and complexity of valuation methods. Here, based on adapting a pre-existing method, we present a new ecosystem service valuation applied to river basins under different characteristics in the biomes of the Atlantic Forest and Brazilian savannah. Our assumptions of ecosystem service valuation concern an analogy based on willingness-to-pay for not marketable services, but adapted by data from the river basins' ecohydrological monitoring. First, the method depicts river ecosystem valuation with probabilistic criteria of both the water yield, as supply, and the grey Water Footprint (greyWF), as demand. Second, we introduced the comparison between water supply and demand carried out on the continuous flow regime and monitored loads in rivers with different land uses, sizes and biomes. Third, this new ecosystem service valuation method enabled us to quickly visualize the possible stages of sustainability concerning the Brazilian legal framework among different basins. The methodology was applied in 12 Brazilian river basins, with drainage areas between 17 and 26,500 km2, and changes in land use with variable percentages of urban (62-92%), forest (51-84%) and agriculture (51-89%) areas. The most polluted basins, with greyWF values far above those allowed, have the most significant, almost asymptotic valuation curves. Results range from a minimum reference value of 61 US$/ha/year for conservation, adapted from the Brazilian Water Producer, to US$ 330 for restoring high polluted basins. The results show the viability of this method and discuss further opportunities for water security, especially for climate change and non-stationary sectorial demands.

Radiotracer binding to brain microsomes determined by thin-layer chromatography.

A thin-layer chromatography (TLC) assay was developed to monitor the interaction of radiotracers with brain microsomes. Murine brain microsomes were coated onto a zone of a TLC strip, the unreacted sites blocked with gelatin, and the radiotracers chromatographed over the microsomes. Radiotracers bound to the microsomes and were separated from the unreacted materials which migrated at or near the solvent front. Up to 80% of the applied radioactivity bound to the brain microsomes when using 99mTc-(d,l) hexamethyl-propyleneamine oxime (HMPAO) and 123I-(S)-2-hydroxy-3-iodo-6-methoxy-N-[(1-ethyl-2-pyrrolidinyl) methyl]-benzamide (123I-IBZM) as tracers. On the other hand, the presumptive negative control materials p-I-15-phenyl-pentadecanoic acid-123I (123I-IPPA) and 99mTc-mercapto-acetyl triglycine (MAG3) bound poorly (7% and 4%, respectively). 99mTc-ethyl cysteinate dimer (ECD) interacted poorly (9.9%), a result thought to be consistent with its known inability to be metabolized by nonprimate brain tissue. Radiolabeled octreotide analogues (radiolabeled with 111In, I-131 or 99mTc) also bound, and the binding could be reduced by excess unlabeled octreotide. Also, chemical modification by acylation of Lys5 in 111In-labeled octreotide led to decreased binding (approximately 70%) compared to the original radiotracer. Chromatography of the various radiotracers over TLC strips coated only with gelatin was used to monitor nonspecific binding and was low and frequently below 5%. This technique does not require wash steps or centrifugation, and assays are rapidly completed. The assay could be useful in monitoring the interaction of radiotracers with brain microsomes and in evaluating and developing new radiotracers.

Anti-colon/ovarian tumor antigen: localization of colon cancer xenografts in athymic rats.

Tumor localization studies in athymic rats bearing human colon tumors were performed using the radioiodinated monoclonal antibody SP-21 and its F(ab')2. Antibody preparations isolated from ascitic fluid and antibody from bioreactor effluent were used in these studies with similar radioimmunolocalization results. The intact antibody had an optimal localization time of 4-8 days after injection, while the F(ab')2 fragments had an optimal localization time of 3-4 days. Whole-body autoradiography, whole-body immunohistochemistry, and scintigraphy confirmed that the intact antibody and the antibody fragments localized preferentially in the tumor. The antibody distribution within the tumor was uniform, and not confined to the periphery, nor to focal areas within the tumor. Dose-response studies were performed with the intact antibody over a range of 10-100 micrograms/kg of total body weight with no clear-cut relationships observed. Comparisons of different radio-iodination methods indicated that the chloramine-T-based methods resulted in preparations with higher tumor uptake.

A comparison of monoclonal antibodies against distinct colon tumor-associated antigens in immunohistochemistry and in tumor localization.

Monoclonal antibodies to colon/ovary tumor antigen (COTA), carcinoembryonic antigen (CEA), colon-specific antigen (CSA), and colon-specific antigen "protein" (CSAp) were evaluated for specificity, reactivity with normal tissues, and tumor localizations using athymic rats bearing xenografted human colon tumors. Radioiodine labeled anti-CSA and anti-COTA retained immunoreactivity and effectively localized the tumors; anti-CSAp retained immunoreactivity, but localized less effectively; and anti-CEA lost most of its immunoreactivity and localized poorly. Of the antibodies tested, anti-COTA showed potential for human colorectal tumor radiolocalization.