A trial of 13-cis-retinoic acid for treatment of squamous cell carcinoma and preneoplastic lesions of the head in cats     

A G Evans  B R Madewell  A A Stannard 《American journal of veterinary research》1985,46(12):2553-2557

Ten cats with a total of 15 cancerous or precancerous lesions were examined for clinical response to and histopathologic changes after treatment with 13-cis-retinoic acid. Before treatment was started, the lesions were graded according to clinical severity and biopsied for histopathologic examination. Serum samples were prepared for determining vitamin A concentrations. For comparison, serum vitamin A concentrations in 10 clinically healthy cats were determined. 13-cis-Retinoic acid (approx 3.0 mg/kg) was given to affected cats once a day for an average of 68 days. At the completion of the therapeutic trial, additional biopsy tissues were obtained for histopathologic examination, and serum was assayed for 13-cis-retinoic acid. Of the 15 lesions examined, only 1 showed partial clinical and microscopic improvement during the therapy period. The mean serum vitamin A concentration of the affected cats was not statistically different from that of the 10 healthy cats. The results of this trial indicated that 13-cis-retinoic acid used at this dosage, daily frequency, and duration did not have therapeutic efficacy for squamous cell carcinomas or preneoplastic lesions in the cat and that the mean serum vitamin A concentration did not differ between the affected cats and clinically healthy cats.  相似文献   

Book announcements     

Hugh Cutler  C. V. Subramanian  John W. Thieret  Richard Evans Schultes  William F. Murison  et al. 《Euphytica》1991,58(2):191-213

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The domestication and improvement of cowpeas (Vigna unguiculata (L.) Walp.)     

W. M. Lush  L. T. Evans 《Euphytica》1981,30(3):579-587

Summary Physiological and morphological characteristics of the two wild and three domesticated subspecies of cowpeas are compared. The wild accessions are alike in having small, hard seeds borne in dehiscent pods, but differ in other characteristics. We suggest that the wild subsp. dekindtiana, from the seasonally-arid tropics, is more likely to have been the progenitor of modern cowpeas than the other wild subspecies (subsp. mensensis), but that subsp. dekindtiana was first cultivated in the humid tropics where its pods are slow to dehisce. Domestication has been associated with changes in the structure of pod valves and seed coats which reduce pod dehiscence and seed hardness. Pods and seeds have increased in size, mainly by increases in the rate of dry weight accumulation, and their increase has been only partly paralleled by increase in the area of subtending leaves. There has been no increase in the maximum photosynthetic rate of leaves, but the duration of their photosynthetic activity has increased. Domesticates are less sensitive than are wild plants to some environmental controls, such as in the response of germination to temperature, but in their flowering responses to daylength both wild and cultivated forms retain sensitivity under conditions where this is of adaptive value.  相似文献   

New insights on the loess/paleosol Quaternary stratigraphy from key sections in the U.S. Midwest     

N.W. Rutter  A.A. Velichko  K.G. Dlussky  T.D. Morozova  E.C. Little  V.P. Nechaev  M.E. Evans 《CATENA》2006

Three key Quaternary loess/paleosol sections were examined in the Missouri Valley (Iowa), Eustis Ash Pit (Nebraska), and in the Wittsburg Quarry (Arkansas) to gain insights into the sedimentation, environment and climate change of the U.S. Midwest. Four loess units are present separated by three well-developed paleosols. Crowley's Ridge Loess (Oxygen Isotope Stage (OIS) 8) is pre-Illinoian in age, and is the oldest loess unit investigated. A well-developed paleosol, interpreted as Yarmouth Soil (OIS 7), is found in this loess in all three sections. Overlying the Yarmouth Soil is Loveland Loess (OIS 6) which has been pedogenically altered by the Sangamon Soil (OIS 5). It has luvisolic properties but a more clayey pedogenic texture than modern luvisols and has no clear eluvial horizon. The overlying Roxana Silt (OIS 4) is pedogenically altered. At Wittsburg and Missouri Valley, the Farmdale Soil (OIS 3) is developed in the Roxana Silt. Based on pedogenic features, we correlate this paleosol to that developed in the Gilman Canyon Formation at Eustis. In Missouri Valley and Eustis sections, the paleosol has chernozemic properties and therefore, the gleyic features observed at Missouri Valley are interpreted as later alterations. Overlying the Farmdale Soil is the widespread Peoria Loess (OIS 2).  相似文献   

Volatilization of demethylmercury and elemental mercury from river Elbe floodplain soils     

D. Wallschläger  H. Hintelmann  R. D. Evans  R. -D. Wilken 《Water, air, and soil pollution》1995,80(1-4):1325-1329

It has been shown that an untreated mercury-polluted floodplain soil (containing 10 μg/g per dry weight (d.w.) total Hg and 12 ng/g (d.w.) monomethylmercury compounds (MMM)) of the river Elbe in Northern Germany contains both dimethylmercury (DMM) and elemental mercury (Hg°). This is the first time ever that DMM has been detected in unmodified soils. A novel purge- and-trap-technique involving a sequential thermodesorption-separation of the two species after trapping on a carbon molecular sieve (CMS) has been developed that allows the determination of the two species DMM and Hg° from aqueous solutions or soil samples by GC-CVAFS. The compounds' identities as Hg-species were confirmed by GC-ICP/MS. A DMM-concentration of 740 pg/g (d.w.) was determined in the soil; the Hg°-concentration was found to be at least four times larger, but could not yet be quantified. Since no precautions against losses via evapoartion were taken during sampling and storage, the original concentrations were probably much higher. Both DMM and Hg° are easily purged with N₂ from soils as well as from soil suspensions, indicating that the two species may readily evaporate from those soils under natural conditions. The amount of DMM determined in the soil suspension was significantly lower (80 pg/g (d.w.)) compared to that in the original soil sample, suggesting that DMM might not be stable under these conditions. Also, it was shown that in natural samples, MMM can be converted into DMM in the presence of sulfide, at S^2?-levels as low as 100 μg/g.  相似文献   

用计算机模拟农药在土壤中的移动和降解   总被引：1，自引：0，他引：1  

陈秋方  A.E.Evans  P.H.Nicholls  G.G.Briggs 《土壤学报》1986,23(4):375-381

本文应用CALF模式,用计算机模拟杀螨剂NC13292在淤积粘壤土中的移动和降解并与田间的实际测定进行比较,结果表明:当仅用吸附系数进行模拟时,经过一段时间以后,模拟的农药移动速度往往大于田间实际移动速度.它暗示农药在土壤中的移动可能存在着两个过程.一是农药在土壤固相与土壤水相之间的分配过程.这一过程对于农药在土壤中的移动起主导作用.二是扩散过程.只有在团粒结构或粘性土壤中,特别是对于极性农药,这一过程才相当重要,在应用吸附系数的同时,再引入一个经验扩散比率常数(0.0125/天),则NC13292在该土壤中移动速度的模拟结果与田间实际测定非常接近.  相似文献   

The availability for the rat of methionine and cystine contained in dry bean seed (Phaseolus vulgaris)     

R J Evans  D H Bauer  K A Sisak  P A Ryan 《Journal of agricultural and food chemistry》1974,22(1):130-133

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Molecular genetics of race non-specific rust resistance in wheat   总被引：1，自引：0，他引：1  

Evans S. Lagudah 《Euphytica》2011,179(1):81-91

Over 150 resistance genes that confer resistance to either leaf rust, stripe rust or stem rust have been catalogued in wheat or introgressed into wheat from related species. A few of these genes from the ‘slow-rusting’ adult plant resistance (APR) class confer partial resistance in a race non-specific manner to one or multiple rust diseases. The recent cloning of two of these genes, Lr34/Yr18, a dual APR for leaf rust and stripe rust, and Yr36, a stripe rust APR gene, showed that they differ from other classes of plant resistance genes. Currently, seven Lr34/Yr18 haplotypes have been identified from sequencing the encoding ATP Binding Cassette transporter gene from diverse wheat germplasm of which one haplotype is commonly associated with the resistance phenotype. The paucity of well characterised APR genes, particularly for stem rust, calls for a focused effort in developing critical genetic stocks to delineate quantitative trait loci, construct specific BAC libraries for targeted APR genes to facilitate robust marker development for breeding applications, and the eventual cloning of the encoding genes.  相似文献   

营口农业水资源现状及利用途径的研究   总被引：1，自引：0，他引：1  

伊卓  那洪民 《辽宁农业职业技术学院学报》2007,9(1):32-33

水是农业生产的命脉,农业水资源短缺,影响到农业生产和农业经济发展,我省是我国水资源严重匮乏的地区之一,营口市又是省内几个重度缺水地区之一,近几年来,营口市在农业水资源利用上面临降水量逐年减少,地表和地下水资源持续下降,农业用水量和耗水增长迅速,水污染严重等一系列问题。因此要通过多途径增加农业水资源总量,节约农业用水,防治水污染,加快农业生态建设和水利设施建设等措施提高农业水资源利用效率。  相似文献   

大庆地区草地退化驱动机制分析   总被引：3，自引：0，他引：3  

臧淑英  那晓东  李雁  冯仲科 《北京林业大学学报》2007,(Z2)

为探讨资源型城市大庆市草地退化驱动机制,找出驱动草地退化的主导因素,为科学保护现有草地资源和有效治理退化草地提供依据和参考.该文在定性描述大庆地区草地退化驱动因素的基础上,运用主成分分析和多元线性回归的方法,选取与草地退化密切相关并比较容易获取的数据作为变量,对大庆地区草地退化的主要影响因素进行了定量分析.根据对草地退化的影响程度,影响因子排序为:畜牧业产值>人口密度>油井个数>总人口>大牲畜存栏>人均居住面积>GDP>工业产值>盐碱、沙化.并且根据大庆地区1988—2001年不同退化程度草地的面积与驱动因子建立多元线性回归模型,对不同退化程度草地面积变化的驱动机制进行了分析.结果表明,不合理的人类活动与石油开采加工的工业化进程占用大量草场是大庆地区草地退化的主要驱动因素,决定着草地生态系统逆向演替的总体趋势.最后根据以上分析提出大庆地区草地退化的防治措施.  相似文献