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1.
Propofol is a potentially useful intravenous anesthetic agent for total intravenous anesthesia (TIVA) in horses. The purpose of this study was to compare the anesthetic and cardiorespiratory effects of TIVA following the administration of propofol alone(P–TIVA) and ketamine–medetomidine–propofol (KM–P–TIVA) in adult horses. The carotid artery was translocated to a subcutaneous position during TIVA with P–TIVA (n = 6) or KM–P–TIVA (n = 6). All horses were premedicated with medetomidine [0.005 mg kg–1, intravenously (IV)]. Anesthesia was induced with midazolam (0.04 mg kg–1 IV) and ketamine (2.5 mg kg IV). All horses were orotracheally intubated and breathed 100% oxygen. The KM drug combination (ketamine 40 mg mL–1 and medetomidine 0.05 mg mL–1) was infused at a rate of 0.025 mL kg–1 hour–1. Subsequently, a loading dose of propofol (0.5 mg kg–1, bolus IV) was administered to all horses; surgical anesthesia (determined by horse response to incision and surgical manipulation, positive response being purposeful or spontaneous movement of limbs or head) was maintained by varying the propofol infusion rate as needed. Arterial blood pressure and HR were also monitored. Both methods of producing TIVA provided excellent general anesthesia for the surgical procedure. Anesthesia time was 115 ± 17 (mean ± SD) and 112 ± 11 minutes in horses anesthetized with KM–P–TIVA and P–TIVA, respectively. The infusion rate of propofol required to maintain surgical anesthesia with KM–P–TIVA was significantly less than for P–TIVA (mean infusion rate of propofol during anesthesia; KM–P–TIVA 0.15 0.02 P–TIVA 0.23 ± 0.03 mg kg–1 minute–1, p = 0.004). Apnea occurred in all horses lasting 1–2 minutes and intermittent positive pressure ventilation was started. Cardiovascular function was maintained during both methods of producing TIVA. There were no differences in the time to standing after the cessation of anesthesia (KM–P–TIVA 62 ± 10 minutes versus P–TIVA 87 ± 36 minutes, p = 0.150). The quality of recovery was good in KM–P–TIVA and satisfactory in P–TIVA. KM–P–TIVA and P–TIVA produced clinically useful general anesthesia with minimum cardiovascular depression. Positive pressure ventilation was required to treat respiratory depression. Respiratory depression and apnea must be considered prior to the use of propofol in the horse. 相似文献
2.
Astaxanthin Normalizes Epigenetic Modifications of Bovine Somatic Cell Cloned Embryos and Decreases the Generation of Lipid Peroxidation 
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下载免费PDF全文 Astaxanthin is an extremely common antioxidant scavenging reactive oxygen species (ROS) and blocking lipid peroxidation. This study was conducted to investigate the effects of astaxanthin supplementation on oocyte maturation, and development of bovine somatic cell nuclear transfer (SCNT) embryos. Cumulus–oocyte complexes were cultured in maturation medium with astaxanthin (0, 0.5, 1.0, or 1.5 mg/l), respectively. We found that 0.5 mg/l astaxanthin supplementation significantly increased the proportion of oocyte maturation. Oocytes cultured in 0.5 mg/l astaxanthin supplementation were used to construct SCNT embryos and further cultured with 0, 0.5, 1.0 or 1.5 mg/l astaxanthin. The results showed that the supplementation of 0.5 mg/l astaxanthin significantly improved the proportions of cleavage and blastulation, as well as the total cell number in blastocysts compared with the control group, yet this influence was not concentration dependent. Chromosomal analyses revealed that more blastomeres showed a normal chromosomal complement in 0.5 mg/l astaxanthin treatment group, which was similar to that in IVF embryos. The methylation levels located on the exon 1 of the imprinted gene H19 and IGF2, pluripotent gene OCT4 were normalized, and global DNA methylation, H3K9 and H4K12 acetylation were also improved significantly, which was comparable to that in vitro fertilization (IVF) embryos. Moreover, we also found that astaxanthin supplementation significantly decreased the level of lipid peroxidation. Our findings showed that the supplementation of 0.5 mg/l astaxanthin to oocyte maturation medium and embryo culture medium improved oocyte maturation, SCNT embryo development, increased chromosomal stability and normalized the epigenetic modifications, as well as inhibited overproduction of lipid peroxidation. 相似文献
3.
Mycosphaerella graminicola causes Septoria tritici blotch (STB) in wheat (Triticum aestivum) and is considered one of the most devastating pathogens of that crop in the United States. Although the genetic structures of M. graminicola populations from different countries have been analyzed using various molecular markers, relatively little is known about M. graminicola populations from geographically distinct areas of the United States and, in particular, of those from spring versus winter wheat. These are exposed to great differences in environmental conditions, length and season of host-free periods, and resistance sources used in geographically separated wheat breeding programs. Thus, there is more likely to be genetic differentiation between populations from spring versus winter wheat than there is among those within each region. To test this hypothesis, 330 single-spore isolates of M. graminicola representing 11 populations (1 from facultative winter wheat in California, 2 from spring wheat in North Dakota, and 8 from winter wheat in Indiana and Kansas) were analyzed for mating type frequency and for genetic variation at 17 microsatellite or simple-sequence repeat (SSR) loci. Analysis of clone-corrected data revealed an equal distribution of both mating types in the populations from Kansas, Indiana, and North Dakota, but a deviation from a 1:1 ratio in the California population. In total, 306 haplotypes were detected, almost all of which were unique in all 11 populations. High levels of gene diversity (H = 0.31 to 0.56) were observed within the 11 populations. Significant (P ≤ 0.05) gametic disequilibrium, as measured by the index of association (rBarD), was observed in California, one Indiana population (IN1), and three populations (KS1, KS2, and KS3) in Kansas that could not be explained by linkage. Corrected standardized fixation index (G″(ST)) values were 0.000 to 0.621 between the 11 populations and the majority of pairwise comparisons were statistically significant (P ≤ 0.001), suggesting some differentiation between populations. Analysis of molecular variance showed that there was a small but statistically significant level of genetic differentiation between populations from spring versus winter wheat. However, most of the total genetic variation (>98%) occurred within spring and winter wheat regions while <2% was due to genetic differentiation between these regions. Taken together, these results provide evidence that sexual recombination occurs frequently in the M. graminicola populations sampled and that most populations are genetically differentiated over the major spring- and winter-wheat-growing regions of the United States. 相似文献
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T Kushiro K Yamashita MA Umar Y Izumisawa K Taguchi WW Muir 《Veterinary anaesthesia and analgesia》2005,32(4):19-19
MKM–OS anesthesia provides general anesthesia with minimum cardiovascular depression in experimental horses. The purpose of this study was to evaluate the effect of MKM–OS anesthesia in clinical cases. Sixty‐eight horses were anesthetized with MKM–OS anesthesia for selective or emergency surgery. The horse physical status was categorized based upon the American Society of Anesthesiologists (ASA) classification scheme. Forty‐four horses were classified as ASA I or II (low‐risk; 30 soft tissue, eight ophthalmic, and six orthopedic surgeries) and 24 horses were classified as ASA III to V (high‐risk; 24 emergency colic surgeries). All horses were administered medetomidine (0.005 mg kg–1 IV) as premedication and anesthetized with ketamine (2.5 mg kg–1 IV) and midazolam (0.04 mg kg–1 IV). The horses were orotracheally intubated and connected to a large animal breathing circuit that delivered oxygen‐sevoflurane and administered the midazolam (0.8 mg mL–1)‐ketamine (40 mg mL–1)‐medetomidine (0.05 mg mL–1) drug combination at a rate of 0.025 mL kg–1 hour–1. Surgical anesthesia was maintained by controlling the dial setting of the sevoflurane vaporizer and achieved by delivering 1.6–1.8% of end‐tidal sevoflurane concentration. All horses were mechanically ventilated during anesthesia. Hypercapnia and hypoxia were not sufficiently improved in high‐risk horses (PaCO2; low‐risk 45–53 mm Hg versus high‐risk 56–60 mm Hg, p < 0.01: PaO2 low‐risk 248–388 mm Hg versus high‐risk 95–180 mm Hg, p < 0.01). Heart rate was significantly higher in high‐risk horses (low‐risk 37–42 bpm versus high‐risk 44–73 bpm, p < 0.01). Dobutamine infusion was required in five low‐risk (11%) and 17 high‐risk horses (68%) to maintain mean arterial blood pressure >70 mm Hg. Eleven high‐risk horses died during the perioperative period (three euthanized during surgery, two died during recovery, six died after recovery). The quality of recovery was good in low‐risk horses and good to satisfactory in high‐risk horses. MKM–OS anesthesia provided excellent surgical anesthesia with minimal to mild cardiovascular depression in low risk‐horses and mild to moderate cardiovascular depression in high risk‐horses. The possibility of preserve cardiovascular function could be the advantage of MKM–OS anesthesia in high‐risk horses. 相似文献
5.
JEP Santos TR Bilby WW Thatcher CR Staples FT Silvestre 《Reproduction in domestic animals》2008,43(S2):23-30
Cattle are fed moderate amounts of long chain fatty acids (FA) with the objective to enhance lactation and growth; however, recent interest on lipid feeding to cows has focused on reproduction, immunity and health. Increasing the caloric density of the ration by fat feeding has generally improved measures of cow reproduction, but when milk yield and body weight losses were increased by fat supplementation, positive effects on reproduction were not always observed. Feeding fat has influenced reproduction by altering the size of the dominant follicle, hastening the interval to first postpartum ovulation in beef cows, increasing progesterone concentrations during the luteal phase of the oestrous cycle, modulating uterine prostaglandin (PG) synthesis, and improving oocyte and embryo quality and developmental competence. Some of these effects were altered by the type of FA fed. The polyunsaturated FA of the n-6 and n-3 families seem to have the most remarkable effects on reproductive responses of cattle, but it is not completely clear whether these effects are mediated only by them or by other potential intermediates produced during rumen biohydrogenation. Generally, feeding fat sources rich in n-6 FA during late gestation and early lactation enhanced follicle growth, uterine PG secretion, embryo quality and pregnancy in cows. Similarly, feeding n-3 FA during lactation suppressed uterine PG release, and improved embryo quality and maintenance of pregnancy. Future research ought to focus on methods to improve the delivery of specific FA and adequately powered studies should be designed to critically evaluate their effects on establishment and maintenance of pregnancy in cattle. 相似文献
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K Yamashita R Igarashi T Kushiro Y Ueyama K Miyoshi MA Umar WW Muir 《Veterinary anaesthesia and analgesia》2005,32(4):13-14
Most methods for determining cardiac output (CO) have limited application in clinical practice due to the invasive techniques required. This study compared the thermodilution technique (TDCO) with three noninvasive methods for determining CO in anesthetized dogs: transthoracic bioimpedance (BICO), partial CO2 rebreathing (NICO), and transesophageal echocardiography (TEECO). TDCO was compared to BICO, NICO, and TEECO in six adult sevoflurane anesthetized beagle dogs (9.1–13.0 kg). All dogs were administered midazolam [0.3 mg kg?1, intravenously (IV)] and butorphanol (0.1 mg kg?1 IV), followed by ketamine (5.0 mg kg–1 IV) and sevoflurane in nitrous oxide (1 L minute–1) and oxygen (1 L minute–1) and mechanically ventilated. Dogs were maintained at 2.2% end‐tidal sevoflurane (ETsev) concentration for instrumentation and baseline measurements. Low (5.0% ETsev), intermediate (3.3% ETsev), and high cardiac output values were achieved by varying the end‐tidal sevoflurane concentration and the administration of dobutamine (3–10 g kg–1 minute–1 and 2.2% ETsev). A minimum of thirty data sets was obtained for each comparison. The correlation coefficients when compared to TDCO were 0.684 for BICO (p < 0.0001), 0.883 for NICO (p < 0.0001), and 0.991 for TEECO (p < 0.0001). Cardiac output values ranged 50–444 mL kg–1 minute–1 for TDCO, 100–253 mL kg–1 minute–1 for BICO, 64–214 mL kg–1 minute–1 for NICO, and 52–401 mL kg–1 minute–1 for TEECO. The differences when compared to TDCO ranged – 62–235 mL kg?1minute?1 for BICO, 18–220 mL kg?1 minute?1 for NICO, and – 35–32 mL kg–1 minute–1 for TEECO. Differences were maximum at the highest CO in BICO and NICO. In conclusion, this study demonstrated that BICO and NICO underestimate CO in sevoflurane anesthetized dogs. TEECO is a viable noninvasive method for determining CO in sevoflurane anesthetized dogs. 相似文献
8.
Vamshidhar Puppala Timothy J. Herrman William W. Bockus Thomas M. Loughin 《Cereal Chemistry》1998,75(1):94-99
Twelve hard red winter wheat cultivars were grown at four locations in central Kansas to evaluate the role of foliar fungal diseases on wheat end-use quality in 1995. Disease was allowed to develop naturally on control plots and was controlled partially on plots treated with a systemic fungicide. After harvest, wheat samples were evaluated for the impact of the disease complex (leaf rust, tan spot, speckled leaf blotch) on physical grain quality, grain protein, milling properties, flour absorption, and peak mixing time. Data were analyzed using a mixed model to account for random (location and block) and fixed (cultivar and fungicide) effects. Location significantly influenced quality characteristics except kernel size and peak mixing time. The magnitudes of variation among random effects on all quality characteristics were larger for location than for the interactions between location × cultivar and location × fungicide. The fixed effects portion of the analysis revealed that the cultivar × fungicide treatment interaction significantly affected test weight, kernel protein, and flour absorption. Fungicide treatment resulted in significant increases in yield and kernel weight. Cultivar significantly affected all quality characteristics except kernel size and peak mixing time. Disease resistance exerted a significant influence on yield and test weight. The economic benefit associated with improved wheat quality from fungicide treatment was variety specific. Three cultivars (TAM 107, Karl 92, and Ike), which account for 50% of the 1997 planted wheat acres in Kansas, demonstrated positive improvements in test weight and protein in response to fungicide treatment. 相似文献
9.
This study evaluated the reactions of seven common C4 grasses of the tallgrass prairie of the USA Great Plains to the economically important wheat pathogens Pyrenophora tritici‐repentis and Gaeumannomyces graminis var. tritici (Ggt) isolated from wheat. The P. tritici‐repentis isolates (race 1) were pathogenic on all grasses tested, but symptom severity was markedly low. Three of the grass species inoculated with Ggt were highly susceptible, while four species exhibited no symptoms. Because measures of connectedness can provide a proxy for population processes, connectedness was evaluated within and among the seven grass species in representative tallgrass prairie environments for all potential pathogen‐sharing patterns. Andropogon gerardii was ubiquitous, so all plant species were well connected to it. Andropogon scoparius (= Schizachyrium scoparium), Sorghastrum nutans and Panicum virgatum were fairly common but specialized to particular environments. Bouteloua curtipendula was uncommon but occurred in all environments, while Buchloë dactyloides and Bouteloua gracilis were uncommon and only occurred in upland sites. Co‐occurrence of plant species was generally not reciprocal in that, for many species pairs, species A rarely occurred without potential exposure to inoculum from species B, while species B commonly occurred without species A. The three grass species susceptible to Ggt may act as sources of inoculum for each other within tallgrass prairie, with the potential to influence fitness, and tallgrass prairie and commercial wheat ecosystems in the Great Plains also have the potential to share both pathogens. 相似文献
10.
Zhang D Bai G Hunger RM Bockus WW Yu J Carver BF Brown-Guedira G 《Phytopathology》2011,101(11):1322-1329
Soilborne wheat mosaic virus (SBWMV) is one of the most important winter wheat pathogens worldwide. To identify genes for resistance to the virus in U.S. winter wheat, association study was conducted using a selected panel of 205 elite experimental lines and cultivars from U.S. hard and soft winter wheat breeding programs. Virus symptoms were evaluated twice in virus-infected fields for the panel at Manhattan, KS in spring 2010 and 2011 and for a subpanel of 137 hard winter wheat accessions at Stillwater, OK in spring 2008. At the two locations, 69.8 and 79.5% of cultivars were resistant or moderately resistant to the disease, respectively. After 282 simple-sequence repeat markers covering all wheat chromosome arms were scanned for association in the panel, marker Xgwm469 on the long arm of chromosome 5D (5DL) showed a significant association with the disease rating. Three alleles (Xgwm469-165bp, -167bp, and -169bp) were associated with resistance and the null allele was associated with susceptibility. Correlations between the marker and the disease rating were highly significant (0.80 in Manhattan at P < 0.0001 and 0.63 in Stillwater at P < 0.0001). The alleles Xgwm469-165bp and Xgwm469-169bp were present mainly in the hard winter wheat group, whereas allele Xgwm469-167bp was predominant in the soft winter wheat. The 169 bp allele can be traced back to 'Newton', and the 165 bp allele to Aegilops tauschii. In addition, a novel locus on the short arm of chromosome 4D (4DS) was also identified to associate with the disease rating. Marker Xgwm469-5DL is closely linked to SBWMV resistance and highly polymorphic across the winter wheat accessions sampled in the study and, thus, should be useful in marker-assisted selection in U.S. winter wheat. 相似文献