仙人掌提取物对吮乳仔猪生产性能影响

仙人掌为仙人掌科仙人掌属植物（Opuntia SPP．）,主要分布在南美、非洲,我国及东南亚和南亚等热带和亚热带地区,     

Antitumor activity of capsaicin on human colon cancer cells in vitro and colo 205 tumor xenografts in vivo

Capsaicin was reported to inhibit cancer cell growth. The aim of this study was to evaluate the antitumor potential of capsaicin by studying antitumor activity in vitro as well as in vivo. The in vitro studies are to examine the effects of capsaicin on human colon cancer colo 205 cells after exposure to capsaicin. The results showed that capsaicin induced cytotoxic effects in a time- and dose-dependent manner and increased reactive oxygen species (ROS) and Ca(2+) but decreased the level of mitochondrial membrane potential (ΔΨ(m)) in colo 205 cells. Data from Western blotting analysis indicated that the levels of Fas, cytochrome c, and caspases were increased, leading to cell apoptosis. Capsaicin decreased the levels of anti-apoptotic proteins such as Bcl-2 and increased the levels of pro-apoptotic proteins such as Bax. Capsaicin-induced apoptosis in colo 205 cells was also done through the activations of caspase-8, -9 and -3. In vivo studies in immunodeficient nu/nu mice bearing colo 205 tumor xenografts showed that capsaicin effectively inhibited tumor growth. The potent in vitro and in vivo antitumor activities of capsaicin suggest that capsaicin might be developed for the treatment of human colon cancer.     

Kinetic and kinematic analysis of the right hind limb during trotting on a treadmill in Labrador Retrievers presumed predisposed or not predisposed to cranial cruciate ligament disease

Objective-To identify gait characteristics during trotting on a treadmill in nonlame Labrador Retrievers presumed predisposed or not predisposed to cranial cruciate ligament disease (CCLD). Animals-Clinically normal Labrador Retrievers presumed predisposed (n = 10) or not predisposed (7) to CCLD. Procedures-The right hind limb of each dog was classified by use of a predictive score equation that combined tibial plateau angle and femoral anteversion angle as presumed predisposed (high score [> -1.5]) or not predisposed (low score [≤ -1.5]) to CCLD. Tarsal joint, stifle joint, and hip joint kinematics, net moments, and powers were computed. Results-The stifle joint was held at a greater degree of flexion in limbs presumed predisposed to CCLD (130.9° vs 139.3°). More power was generated by muscles acting on the stifle joint in the early stance phase of limbs presumed to be predisposed to CCLD (2.93 vs 1.64 W/kg). The tarsal joint did not reach the same degree of extension in limbs presumed predisposed to CCLD, compared with that in limbs presumed not predisposed to CCLD (179.0° vs 161.0°). Velocity, stance time, vertical and craniocaudal forces, angular velocities, and net joint muscle moments did not differ between groups. Conclusions and Clinical Relevance-Gait mechanics of dogs with high (> -1.5) and low (≤ -1.5) tibial plateau angle and femoral anteversion angle scores were characterized on a treadmill, which may help in the identification of dogs predisposed to CCLD.     

Phloem mobility of xenobiotics VI. A phloem-mobile pro-nematicide based on oxamyl exhibiting root-specific activation in transgenic tobacco

Phloem mobility is a desirable attribute for pesticides in many applications, and the physicochemical properties necessary for phloem mobility are now well understood. However, attempts to derivatize pesticides to make them phloem mobile are often frustrated by a concomitant loss of activity. This study describes a phloem-mobile pro-nematicide, a hydroxymethyloxamyl glucuronide (JR522) coupled with an in-situ activation mechanism in transgenic tobacco expressing Escherichia coli β-glucuronidase in its root tips. When applied foliarly to the transgenic tobacco, JR522 and its methyl ester (JM775) showed greater nematicidal activity than oxamyl against root-knot nematodes. This example of combining pro-pesticide chemistry with crop genetic engineering for site-specific activation provides a model system for demonstrating how to circumvent the often mutual exclusivity of phloem mobility and pesticidal activity. Additional advantages of this scheme include the potential mammalian safety of the propesticide, as exhibited by JR522 in this study, and a high degree of site-specific release of xenobiotics in plants.     

Development and validation of a questionnaire for measuring behavior and temperament traits in pet dogs

OBJECTIVE: To develop and validate a questionnaire to assess behavior and temperament traits of pet dogs. DESIGN: Cross-sectional survey of dog owners. Animals-1,851 dogs belonging to clients of a veterinary teaching hospital or members of national breed clubs and 203 dogs examined by canine behavior practitioners because of behavior problems. PROCEDURE: Owners were asked to complete a questionnaire consisting of 152 items eliciting information on how dogs responded to specific events and situations in their usual environment. Data from completed questionnaires were subjected to factor analysis, and the resulting factors were tested for reliability and validity. RESULTS: Factor analysis yielded 11 factors from 68 of the original questionnaire items that together accounted for 57% of the common variance in questionnaire item scores. Reliability was acceptable for all but 1 of these factors. Behavior problems in 200 of the 203 dogs with behavior problems could be assigned to 7 diagnostic categories that matched 7 of the factors identified during factor analysis of questionnaire responses. Dogs assigned to particular diagnostic categories had significantly higher scores for corresponding questionnaire factors than did those assigned to unrelated diagnostic categories, indicating that the factors were valid. Validity of the remaining 4 factors could not be examined because of a lack of information on dogs with behavior problems related to these factors. CONCLUSIONS AND CLINICAL RELEVANCE: Findings suggest that the resulting 68-item questionnaire is a reliable and valid method of assessing behavior and temperament traits in dogs. The questionnaire may be useful in screening dogs for behavior problems and in evaluating the clinical effects of various treatments for behavior problems.     

Comparison of two swine Mycoplasma hyopneumoniae enzyme-linked immunosorbent assays for detection of antibodies from vaccinated pigs and field serum samples.

Mycoplasma hyopneumoniae (Mhyo) causes mycoplasmal pneumonia, an economically important disease of swine. Serodiagnosis of Mhyo is based on the current available commercial enzyme immunoassays for detection of swine antibodies against Mhyo, which are the indirect enzyme-linked immunosorbent assay (ELISA) and the blocking ELISA (B-ELISA). Because of the limited information available for these ELISAs, these 2 assays were compared by testing 347 serum samples collected from vaccinated pigs at 0, 13, 28, 43, and 62 days postimmunization (DPI), 50 samples from nonvaccinated pigs, and 1,013 field serum samples. The results of comparison study showed that the specificity for both ELISAs was 99.2% generated from 139 non-vaccinated negative samples. The sensitivities for indirect ELISA generated from samples collected from animals that received the vaccine at DPI 13, 28, 43, and 62 were 0%, 95.7%, 88.4%, and 92.6%, respectively, whereas the sensitivities for B-ELISA were 0%, 98%, 100%, and 97%, respectively. The overall agreement of 96.7% and 80.3% was generated between 2 ELISAs from negative and vaccinated pigs and from field samples, respectively.     

Characterization of Erwinia chrysanthemi, the soft-rot pathogen of white-flowered calla lily, based on pathogenicity and PCR-RFLP and PFGE analyses

Isolates of Erwinia chrysanthemi from Zantedeschia aethiopica (white-flowered calla lily) induced symptoms of soft rot on inoculated cv. Innocence flower-stem segments. Isolates from Phalaenopsis aphrodite and potato caused mild symptoms, while those from green onion and celery produced no symptoms. In addition to pathogenicity, the isolates were further characterized at the molecular level. A specific oligonucleotide primer set was designed for the detection of the pelZ gene of E. chrysanthemi . All E. chrysanthemi isolates tested contained pelZ as determined by PCR amplification. No amplification was observed with other Erwinia spp. The pelZ of E. chrysanthemi isolate S3-1 from Z. aethiopica was cloned, sequenced and compared with the nucleotide sequence of pelZ in GenBank. A point mutation produced an Ahd I restriction site, leading to the development of a PCR-RFLP assay to discriminate white-flowered calla lily isolates from others of E. chrysanthemi . Furthermore, macrorestriction analysis by modifying a pulsed-field gel electrophoresis (PFGE) protocol used by PulseNet revealed the genomic variation within E. chrysanthemi . After digestion with the restriction enzyme Xba I, white-flowered calla lily E. chrysanthemi isolates could be easily distinguished from other isolates. Differences in virulence, combined with PCR-RFLP and PFGE analyses, suggest that white-flowered calla lily E. chrysanthemi isolates are a new strain or pathotype in Taiwan.     

Digoxin- and monensin-induced changes of intracellular Ca2+ concentration in isolated guinea-pig ventricular myocyte

This study was undertaken to determine the possible mechanisms of actions of monensin and digoxin by using isolated guinea-pig ventricular myocytes. Since Ca2+ is the major signal for triggering contraction of cardiac muscle, the objective of this study was to determine whether monensin and digoxin affect the [Ca2+]i of cardiac myocytes and if so is this effect due to an increase in [Na+]i. Three different concentrations of digoxin (0.3, 1 and 3 micromol/l) and three different concentrations of monensin (0.3, 1 and 3 micromol/l) were used. Each treatment was monitored for two hours by using computerized fluoroscopy. Both digoxin and monensin increased the [Ca2+]i and accelerated the onset time of [Ca2+]i increase in a dose-dependent manner. Normal myocytes (loaded with fura-2 for 30 min before the treatment) were also compared with 'weakened' myocytes (loaded with fura-2 for 3 h before the treatment to create a 'weakened' condition). It was found that although 0.3 micromol/l monensin and digoxin did not change the [Ca2+]i in normal myocytes, they increased the [Ca2 +]i in 'weakened' myocytes. Finally, a Na+-free medium was used to demonstrate the effect of [Na+]o on both monensin- and digoxin-induced increases in [Ca2+]i. It was found that digoxin did not increase the [Ca2+]i in the Na+-free medium. Although monensin increased the [Ca2+]i in the Na+-free solution, this increase was not as large as in the Na+-containing medium. The results of the study led to the conclusion that the positive inotropic effect of digoxin depends on [Na+]o. However, monensin increases [Ca2+]i in Na+-dependent and -independent ways. An addition conclusion was that 'weakened' myocytes are more sensitive to the monensin and digoxin treatment than normal myocytes.