Effects of stream-crossing by a pipeline on the benthic macroinvertebrate communities of a small mountain stream

Aquatic environmental impact associated with stream-crossing by a pipeline was monitored at Archibald Creek, B.C. for two years. Water chemistry and benthic macroinvertebrates were used as monitoring tools. Results indicated that impacts arising from stream-crossing were short-term and non-residual.Funded by a contract from Canadian Arctic Gas Study Limited, calgary, to Aquatic Environments Limited, Calgary.Aquatic Environments Limited, Calgary.Aquatic Environments Limited, Calgary.     

The uptake of liposome-entraped 125I-labelled poly(vinylpyrrolidone) by rat jejunum in vitro

The uptake of free and liposome-entrapped ¹²⁵I-labelled poly(vinylpyrrolidone) was measured in an intestinal sac preparation from adult rats. An an equal concentration of ¹²⁵I-labelled poly(vinylpyrrolidone), the rate of uptake of the liposome-entrapped material was four times that of the free macromolecule.     

High resolution scanning electron micrographic study of dissociated mouse taste cells

New techniques for enzymatic dissociation of mammalian tastecells allowed us to study, for the first time, the morphologyof murine taste receptor cells using high resolution scanningelectron microscopy. Cell shape varied from spindle to bipolarto lamellar, similar to shapes previously described in cellsfrom amphibian taste buds. Cell length varied from 19 to 65µm (39 ± 19 µm), with width averaging 6 ±3.4 µm. A rare picture of the apical microvilli of a tastereceptor cell, and a view of microvilli within a taste pore,suggest that at any given time, five to eight taste cells maybe exposed to the oral cavity. Assuming a cell life-span of10 days, and 50 cells per bud, all of which eventually reachthe taste pore, one can calculate that the average cell is exposedto the oral environment for