畜禽新营养素-ω-3多不饱和脂肪酸

饲料中ω－3多不饱和脂肪酸的含量都较低，而ω－6多不饱和脂肪酸的含量却较高。鱼粉和鱼油中都富含ω－3多不饱和脂肪酸。它们是平衡ω－6多不饱和脂肪酸；ω－3多不饱和脂肪酸比的最有效的途径。而平衡的ω－6多不饱和脂肪酸；ω－3多不饱和脂肪酸比可提高家畜的健康水平和繁殖力。     

Evidence against hydrogen-based microbial ecosystems in basalt aquifers

It has been proposed that hydrogen produced from basalt-ground-water interactions may serve as an energy source that supports the existence of microorganisms in the deep subsurface on Earth and possibly on other planets. However, experiments demonstrated that hydrogen is not produced from basalt at an environmentally relevant, alkaline pH. Small amounts of hydrogen were produced at a lower pH in laboratory incubations, but even this hydrogen production was transitory. Furthermore, geochemical considerations suggest that previously reported rates of hydrogen production cannot be sustained over geologically significant time frames. These findings indicate that hydrogen production from basalt-ground-water interactions may not support microbial metabolism in the subsurface.     

Enhanced Lipid Stability in Whole Wheat Flour by Lipase Inactivation and Antioxidant Retention

The purpose of this study was to determine the effectiveness of dry heat, steam, and microwave treatments in decreasing lipase activity, while retaining antioxidant activity, to stabilize whole wheat flour against lipid degradation during storage. Bran was heat‐treated in 230‐g batches using four levels (exposure times) for each of the three treatment methods. Lipase activity and antioxidant activity were quantified for all treatment combinations. None of the treatments significantly decreased antioxidant activity; the levels determined to be optimal, inasmuch as further heating did not significantly decrease lipase activity, were 25 min of dry heat, 60 sec of microwave (1000W), and 60 sec of steam. These treatments effectively decreased lipase activity by 74, 93, and 96%, respectively. Optimum treatments were evaluated for acceptance using a consumer sensory panel during a 12‐month storage period. No significant differences in acceptance were found between the control and any of the samples either at baseline or after storage. This suggests that whole wheat flour can be stabilized against lipolysis by utilizing the treatments described in this study without decreasing antioxidant activity, and that manufacturers may utilize these treatments without risking decreased consumer acceptance.     

Genetic manipulation for enhancing calcium content in potato tuber

Increased calcium (Ca) in potatoes may increase the production rate by enhancing tuber quality and storability. Additionally, increased Ca levels in important agricultural crops may help ameliorate the incidence of osteoporosis. However, the capacity to alter Ca levels in potato tubers through genetic manipulations has not been previously addressed. Here we demonstrate that potato tubers expressing the Arabidopsis H+/Ca2+ transporter sCAX1 (N-terminal autoinhibitory domain truncated version of CAtion eXchanger 1) contain up to 3-fold more Ca than wild-type tubers. The increased Ca appears to be distributed throughout the tuber. The sCAX1-expressing potatoes have normally undergone the tuber/plant/tuber cycle for three generations; the trait appeared stable through successive generations. The expression of sCAX1 does not appear to alter potato growth and development. Furthermore, increased Ca levels in sCAX1-expressing tubers do not appear to alter tuber morphology or yield. Given the preponderance of potato consumption worldwide, these transgenic plants may be a means of marginally increasing Ca intake levels in the population. To our knowledge, this study represents the first attempts to use biotechnology to increase the Ca content of potatoes.     

Gallbladder mucocele in dogs: 30 cases (2000-2002)

OBJECTIVE: To determine long-term outcome of dogs with gallbladder mucocele. DESIGN: Retrospective study. ANIMALS: 30 dogs with gallbladder mucocele, including 23 that underwent cholecystectomy. PROCEDURE: Medical records were reviewed for signalment, history, and clinical, ultrasonographic, and surgical findings. Follow-up information was obtained for all dogs that survived the perioperative hospitalization period. RESULTS: 23 dogs had signs of systemic illness; 7 had no clinical signs. Median values for serum activities of alanine aminotransferase and alkaline phosphatase, serum total bilirubin concentration, and total WBC count were significantly higher among dogs with gallbladder rupture than among dogs without rupture. Sensitivity of sonography for detection of rupture was 85.7%. Overall perioperative mortality rate for dogs that underwent cholecystectomy was 21.7%; mortality rate was not significantly greater for dogs with rupture. Aerobic bacteria were isolated from the bile or gallbladder wall in 8.7% of dogs. All 18 dogs discharged from the hospital had complete resolution of clinical signs. In dogs that underwent in-hospital reexamination, serum liver enzyme activities were significantly decreased, compared with preoperative activities. Persistent increases in serum activities of 1 or more liver enzymes were detected in 9 of 12 dogs; 6 of 12 dogs had persistent abnormalities in hepatic echogenicity. Mean follow-up period was 13.9 months. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that cholecystectomy is an effective treatment for gallbladder mucocele. Although perioperative mortality rate is high, prognosis after discharge from the hospital is excellent. Rupture of the gallbladder warrants emergency surgical intervention but does not preclude a positive outcome.