ITREOH building of regional capacity to monitor recreational water: development of a non-commercial microcystin ELISA and its impact on public health policy

In 2001, a University of California, Davis-University of the Republic, Montevideo, partnership created a Fogarty ITREOH program to exploit the potential of ELISA to provide a low-cost environmental analysis attractive to economically distressed countries of temperate South America. This paper describes the development and validation of an ELISA method for the determination of Cyanobacteria microcystin toxins in algal blooms, which release hepatotoxic metabolites that can reach toxic levels in rivers, lakes, or coastal estuaries used for recreation or water supplies. The assay made possible the first systematic monitoring of water from the Rio de la Plata at Montevideo over two summers. The project has been integrated into a bi-national effort to monitor the Rio de la Plata.     

Bleomycin-induced pulmonary fibrosis: correlation of biochemical, physiological, and histological changes

Rats (275–300 g) were intratracheally instilled with 0.38, 0.75, or 1.5 units of bleomycin sulfate. One, two, and three weeks later lung damage was evaluated using a variety of indices, including body weight, right apical lung lobe wet weight, protein- and collagen-synthesis rates by lung minces, lung hydroxyproline content, lung compliance, and lung histology. Several parameters in the high-dose bleomycin group also were evaluated 5 and 8 weeks after instillation. Most of the assays showed a dose-response effect. However, biochemical assays did not correlate with physiological changes 5 and 8 weeks after instillation.     

Chromate inhibition of metabolism by rat tracheal explants. II. In vivo exposures.

We have previously shown that incubation of rat tracheal slices in tissue culture medium containing 0.4?2.6 mm (mmol/liter) Na₂CrO₄ causes inhibition of secretion of mucus glycoproteins by such explants. At concentrations of Na₂CrO₄ of 0.27 mm and above, the inhibition of secretion rate could be correlated with damage to the tracheal epithelium evaluated by histopathologic observations. In the present study we extend these findings by determination of the effects of Na₂CrO₄, administered to rats in vivo (for 24 hr) as an aerosol with a mass median aerodynamic diameter of 1–2 μm at concentrations of 0.051 and 0.173 mmol/m³, upon the previously evaluated parameters. With the aid of several simplifying assumptions, the in vivo dosages of Na₂CrO₄ can be compared with the equivalent concentrations to which trachaea were exposed in vitro in the earlier study. When such calculations are made, there is an excellent correlation between the toxicity observed at equivalent dosages of Na₂CrO₄in vivo and in vitro. Such data may be used to calculate the tracheal deposition factor, F, the percentage of the total Na₂CrO₄ mass from the inhaled aerosol deposited upon the trachea. The value of F so obtained, 0.4?0.7%, compares favorably with results calculated previously on the basis of deposition of radiolabeled fused aluminosilicate particles. Thus, the tracheal explant technique may prove useful as a dosimeter for studying the quantitative in vivo deposition of freely diffusable, water-soluble agents on various airway surfaces of experimental animals.     

Vergleichende Untersuchungen zur Bestimmung von Cyclobarbital in Organen und Körperflüssigkeiten

Zusammenfassung Ein Vergleich von vier Barbituratisolierungsverfahren im Falle einer akut tödlichen Cyclobarbitalvergiftung ergibt eine Überlegenheit der Dresslerschen Methode bezüglich der Reinheit des erhaltenen Barbiturats. Dialyse und Verdauung werden bei anschließender photometrischer Bestimmung empfohlen. Die gefundene niedrige Leberkonzentration wird auf postmortale Abbauvorgänge zurückgeführt.     

Ozone-induced alterations in collagen metabolism of monkey lungs: Use of biopsy-obtained lung tissue

Open-chest biopsies of lung were performed on three cynomolgus monkeys (Macaca fascicularis) 4–6 weeks before and immediately after exposure to 1.5 ppm of ozone for 1 week. Two control monkeys were subjected to comparable procedures, but were exposed to filtered air for 1 week immediately prior to the second biopsy. Collagen synthesis rate of each lung biopsy specimen was determined. Enhanced rates of collagen synthesis were observed in the lung biopsy specimens obtained from the monkeys exposed to ozone; elevated rates of collagen synthesis were not observed in lung biopsy specimens from the two monkeys undergoing identical surgical procedures but not exposed to ozone. We conclude that exposures of monkeys to high levels of ozone caused increased rates of collagen synthesis in their lungs, suggesting that the ozone-induced fibrotic changes observed previously in rat lungs also occur in lungs anatomically similar to those of humans. This experimental design, in which each animal serves as its own control, is a practical way to perform such exposure experiments using small numbers of valuable animals.