Evidence for exposure to selenium by breeding interior snowy plovers (Charadrius nivosus) in saline systems of the Southern Great Plains.

Interior snowy plover (Charadrius nivosus) population declines and deteriorating conditions throughout the Southern Great Plains (SGP) of Texas, New Mexico, and Oklahoma may be linked to environmental contaminants. Concentrations of V, As, Cd, Pb, and Se were quantified in breeding snowy plover blood, feathers (5th primary; P5), and potential prey (tiger beetles [Cicindela circumpicta and C. togata]). Se was (a) most commonly detected relative to other quantified elements and (b) frequently quantified at levels exceeding background or toxicity thresholds. Of samples greater than instrumentation detection limits, 98% of snowy plover blood and 22% of feather samples were greater than Se toxicity thresholds of 1 ppm ww for blood and 5 ppm dw for feathers (blood quantifiable range: 0.83-15.12 ppm; feathers quantifiable range: 1.90-27.47 ppm). Almost all tiger beetle Se concentrations were below reported invertebrate thresholds of 30 ppm dw (quantifiable range: 0.54-45.84 ppm). Snowy plover blood Se concentrations were related to sex, individual body condition, and local tiger beetle Se concentrations, while plover P5 Se concentrations were related to state, sex, and presence of body molt. Tiger beetle Se concentrations were related to individual study sites in Texas. These results provide some of the first evidence of Se exposure risk for interior snowy plovers nesting in saline lake and alkali flat environments of the SGP. Future efforts should focus upon specific Se uptake pathways during breeding and nonbreeding seasons, as snowy plovers breeding in the SGP appear to be exposed to Se throughout their annual cycle.

Polygalacturonase isozymes from Botrytis cinerea grown on apple pectin.

Five isozymes (four acidic and one basic) of polygalacturonase were separated by chromatofocusing from the culture filtrate of Botrytis cinerea grown on apple pectin. The isozymes, designated as Polygalacturonase I to V, have isoelectric points of 9.7, 4.9, 4.6, 3.7, and 2.7, respectively, with Polygalacturonase III exhibiting the highest specific activity. Polygalacturonase I appeared to function as an endo-polygalacturonase while the other four isozymes act as exo-polygalacturonases. The pH optima of the isozymes range from pH 4.5 to 5.5 with Polygalacturonase V being less sensitive to higher pH compared with the rest of the isozymes.

Effect of mechanical bowel preparation on anastomotic integrity following low anterior resection in dogs.

To assess the effect of mechanical bowel preparation on anastomotic integrity after low anterior resection, 36 mongrel dogs were randomized to have low anterior resection with or without mechanical bowel preparation. All dogs received prophylactic antibiotics and anastomotic integrity was assessed on the ninth postoperative day by barium enema, inspection of anastomoses for defects after careful excision at laparotomy, and anastomotic bursting pressures. Bursting pressures were significantly higher (P less than 0.005) in the group with bowel preparation. Anastomotic defects were present in 13 per cent of animals with bowel preparation and 47 per cent without bowel preparation (P = 0.057). Pelvic abscess and death from peritonitis occurred in 6 per cent of the group with bowel preparation and 29 per cent of the unprepared group. Mechanical bowel preparation significantly enhanced anastomotic integrity and reduced complications in this model.