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91.
Correa Mdo A Aguiar AJ Neto FJ Mendes Gda M Steagall PV Lima AF 《American journal of veterinary research》2007,68(9):932-940
OBJECTIVE: To evaluate the effects of 2 remifentanil infusion regimens on cardiovascular function and responses to nociceptive stimulation in propofol-anesthetized cats. ANIMALS: 8 adult cats. PROCEDURES: On 2 occasions, cats received acepromazine followed by propofol (6 mg/kg then 0.3 mg/kg/min, i.v.) and a constant rate infusion (CRI) of remifentanil (0.2 or 0.3 microg/kg/ min, i.v.) for 90 minutes and underwent mechanical ventilation (phase I). After recording physiologic variables, an electrical stimulus (50 V; 50 Hz; 10 milliseconds) was applied to a forelimb to assess motor responses to nociceptive stimulation. After an interval (> or = 10 days), the same cats were anesthetized via administration of acepromazine and a similar infusion regimen of propofol; the remifentanil infusion rate adjustments that were required to inhibit cardiovascular responses to ovariohysterectomy were recorded (phase II). RESULTS: In phase I, heart rate and arterial pressure did not differ between remifentanil-treated groups. From 30 to 90 minutes, cats receiving 0.3 microg of remifentanil/kg/min had no response to noxious stimulation. Purposeful movement was detected more frequently in cats receiving 0.2 microg of remifentanil/kg/min. In phase II, the highest dosage (mean +/- SEM) of remifentanil that prevented cardiovascular responses was 0.23 +/- 0.01 microg/kg/min. For all experiments, mean time from infusion cessation until standing ranged from 115 to 140 minutes. CONCLUSIONS AND CLINICAL RELEVANCE: Although the lower infusion rate of remifentanil allowed ovariohysterectomy to be performed, a CRI of 0.3 microg/kg/min was necessary to prevent motor response to electrical stimulation in propofol-anesthetized cats. Recovery from anesthesia was prolonged with this technique. 相似文献
92.
White G McClure SR Sifferman R Holste JE Fleishman C Murray MJ Cramer LG 《Journal of the American Veterinary Medical Association》2007,230(11):1680-1682
OBJECTIVE: To determine the effects of 8 days of light to heavy exercise on gastric ulcer development in horses and determine the efficacy of omeprazole paste in preventing gastric ulceration. DESIGN: Randomized, controlled, multicenter clinical trial. ANIMALS: 102 horses with normal-appearing gastric mucosa on endoscopic examination that were in light to heavy training. PROCEDURES: Horses at 4 trial locations were allocated into replicates and sham dosed orally (empty syringe) or treated with a paste formulation of omeprazole (1 mg/kg [0.45 mg/ lb], PO) once daily for 8 days. Training regimens varied among locations and included early training for western performance events; walking, trotting, and cantering in a mechanical exerciser; and race training (2 locations). Prevalences of gastric ulceration at the completion of the 8-day treatment period were compared between groups. RESULTS: At the end of the 8-day treatment period, the proportion of omeprazole-treated horses free from gastric ulceration (88%) was significantly higher than the proportion of sham-dosed horses free from gastric ulceration (27%). CONCLUSIONS AND CLINICAL RELEVANCE: Results showed that horses in light to heavy training for as short as 8 days were at risk of developing gastric ulcers and that administration of omeprazole paste decreased the incidence of gastric ulcers. 相似文献
93.
94.
95.
Roger Hull 《Euphytica》1994,75(3):195-205
Summary Plant viruses cause considerable losses to crops and none of the three current approaches to disease control are likely to give the long-term answer. The new concept of non-conventional protection, in which the expression of a viral or virus-related sequence in the plant genome interferes with the virus infection cycle, holds considerable promise for designing new resistance or protection genes. A series of targets in the viral genome is identified and a range of mechanisms for attacking those targets is discussed. There are several current systems which have been proved to give protection, at least to a certain extent, and many systems which are being researched upon for the future. Some of these are described to give a picture of the current situation and of the thinking for the future. The problems of field deployment of the transgenic plants are discussed, especially those associated with the risk to the environment. Various questions which molecular biologists and plant breeders will have to consider include what are desirable characters to have in protection genes and how these new genes should be deployed. 相似文献
96.
Roger G. Pertwee 《Euphytica》2004,140(1-2):73-82
Summary Cannabis is the unique source of a set of at least 66 compounds known collectively as cannabinoids. Of these, most is known about the pharmacology of 9-tetrahydrocannabinol (9-THC), the main psychoactive constituent of cannabis, and about cannabidiol (CBD), which lacks psychoactivity. Accordingly, this paper focuses on the pharmacological and therapeutic targets of these two cannabinoids. Many of the effects of 9-THC are mediated by cannabinoid receptors of which at least two types, CB1 and CB2, are present in mammalian tissues. Endogenous agonists for cannabinoid receptors have also been discovered. CB1 receptors are present at the terminals of central and peripheral neurones, where they modulate transmitter release. They also exist in some non-neuronal cells. CB2 receptors are expressed mainly by immune cells, one of their roles being to alter cytokine release. 9-THC also appears to have non-CB1, non-CB2 pharmacological targets. It is already licensed for clinical use in the U.S.A. as an anti-emetic and appetite stimulant and both 9-THC and 9-THC-rich cannabis extracts show therapeutic potential as neuroprotective and anticancer agents and for the management of glaucoma, pain and various kinds of motor dysfunction associated, for example, with multiple sclerosis and spinal cord injury. CBD has much less affinity for CB1 and CB2 receptors than 9-THC and its pharmacological actions have been less well characterized. Potential clinical applications of CBD and CBD-rich cannabis extracts include the production of anti-inflammatory and neuroprotective effects, the management of epilepsy, anxiety disorders, glaucoma and nausea, and the modulation of some effects of 9-THC. 相似文献
97.
Genetic relationships among 18 accessions, including 16 of Ananas and two of Pseudananas, were investigated using RAPD molecular markers. The procedure for DNA extraction was adapted from the method of Dellaporta
et al. (1983) where an incubation in proteinase K and a purification step were included. From the total of 148 markers scored,132
(89.2%) were polymorphic. The similarity matrix was used for cluster analysis. The phenogram developed from the RAPD bands
showed that for most of the cases, the accessions within a species grouped together. Nevertheless, a moderate infraspecific
genetic variation was observed. For example, DNA data grouped all A. comosus accessions with a mean similarity coefficient of 0.85. Comparable results were obtained with all other species investigated.
The highest genetic divergence was found withinA. lucidus where the mean similarity coefficient among accessions was0.75. A similar level of genetic polymorphism was observed among
species,therefore, a definition about which species were involved in the constitution of A. comosus genotypes was not possible. These results agree with the breeders standpoint suggesting that all Ananas species belong to the primary gene pool of pineapple.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
98.
No information is available on the effects of different biomass yield environments on selection efficiency in switchgrass
(Panicum virgatum L.) breeding improvement. This study was conducted to assess the effects of high- and low-biomass yield environments (HYE
and LYE, respectively) on recurrent selection for general combining ability (RSGCA) in a lowland population of switchgrass
(NL-94). The top 14 of 65 NL-94 C0 parent plants were selected based on biomass yield of half-sib (HS) progeny tested for one post-establishment year under HYE
and LYE conditions. Nine of the 14 C0 parent plants were the same based on HS performance under HYE and LYE. Selected plants were intercrossed to produce NL-94
HYE and NL-94 LYE C1 populations. One hundred and twenty-five HS C1 progeny families (60 NL-94 HYE and 65 NL-94 LYE) were evaluated for biomass yield for 3 years (2002–2004) under HYE and LYE
conditions. The HYE produced about 2.5 times higher biomass yields than the LYE in both C0 and C1 HS progeny tests. Estimated additive genetic variance and predicted gains from selection (ΔG) were high in the C1 populations indicating that RSGCA should achieve higher biomass yields. Mean biomass yields of C1 HS families originating from the LYE protocol were significantly higher than those of families originating from the HYE protocol
in both HYE and LYE performance tests, suggesting greater selection response under LYE in the C0 population. The estimates of narrow-sense heritability (
) and ΔG from the C1 populations indicate that positive response to selection for biomass yield is possible in subsequent cycles of selection
under either HYE or LYE, with a possible small advantage for HYE. 相似文献
99.
Solanum lycopersicoides Dun. is a wild nightshade native to Chile and Peru that possesses many traits of potential interest
to tomato breeders, including environmental stress tolerance, resistances to disease and insect pests, and certain fruit quality
characteristics. Sexual and somatic hybrids with the cultivated tomato (Lycopersicon esculentum Mill.) are readily obtained,
yet have a strong tendency towards male-sterility combined with unilateral incompatibility, barriers that have deterred breeding
efforts in the past. We report herein the synthesis of a partially male-fertile F1 hybrid by sexual crosses between tomato and a recently collected population of S. lycopersicoides. Over 280 BC1 plants were obtained by directed backcrossing to tomato at the diploid level, of which 58 were sufficiently fertile to permit
selfing or additional backcrosses. The transmission of S. lycopersicoides genetic markers into a uniform L. esculentum background
was confirmed with 24 isozyme or morphological loci on 11 of the 12 alien chromosomes. Potentially useful tolerance to gray
mold (Botrytis cinerea) was demonstrated by inoculation of stem cuttings with mycelial plugs: at 6 days post-inoculation,
the intergeneric hybrid showed little evidence of disease progression and the length of stem lesions averaged only one third
that of susceptible controls.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
100.
Summary The main constraint of using Ogura male-sterile cytoplasm in Brassica is the induction of leaf yellowing at low temperature and the low seed set. But whether or not the cytoplasm can disturb the general commerical performance of the plants is not well-known. Therefore, this work was carried out with the purpose of evaluating Ogura cytoplasmic male-sterile cabbage hybrids and compare them to genomic similar male-fertile ones and to the most popular cabbage hybrid cultivated in Brazil. Harvest data showed an effect of the cytoplasm on reducing plant and head weight, core length and head length and width, although not altering heading index, shape and core indexes, nor head compactness. On the other hand, it was observed also that a careful selection of the parental lineages can produce male-sterile hybrids as good as their male-fertile analogues. All the evaluated hybrids were similar or better than the check for the characteristics under study.Abbreviations dat -
days after transplanting
- CNPH -
National Center for Vegetable Crops Research 相似文献