Pregnancy impairs ketone body disposal in late gestating ewes: implications for onset of pregnancy toxaemia

The impact of pregnancy on ketone body disposal during a hyperketonaemic clamp was examined by tracer isotope dilution techniques in seven 12 h fasted sheep in three reproductive states, in the dry non-gestating period, late in gestation and during early lactation. After a sampling period of 60 min under basal conditions a DL-BHB racemate solution was continuously infused intravenously for 3 h at rates of 14.3-24.3 micromol/(kg min) to elevate the D-BHB concentration in blood plasma to values between 5 and 7 mmol/l. Two separate experiments were carried out with the same sheep in each of the three reproductive states. During pregnancy three ewes were pregnant with a single lamb and four ewes carried twins. Maximal D-BHB turnover rates fell significantly in late gestation by 26% relative to early lactation and by 22% when compared with the dry non-pregnant state. Reduction of maximal D-BHB disposal rate during late gestation was accompanied by a significant 297% (p<0.005) and a non-significant 49% increase in the basal BHB concentration in blood, a non-significant 10% and 4% decrease in the rate constant of D-BHB turnover and a non-significant 24% and 13% rise in the incremented increase of D-BHB concentration per unit D-BHB infusion, relative to the dry and the lactating period, respectively. Induction of hyperketonaemia significantly lowered NEFA and glycerol concentrations in blood by 67% and 57%, respectively, compared to the pre-infusional concentrations. The magnitude of this effect was the same in all reproductive states and was explained as a direct antilipolytic action of D-BHB on adipose tissue. It is concluded that the reduced ability of the late gestating ewe to utilize D-BHB promotes hyperketonaemia. Since hyperketonaemia exerts several adverse effects, e.g. on energy balance and glucose metabolism it appears that the impairment of ketone bodies disposal in late pregnancy facilitates development of pregnancy toxaemia, especially in ewes carrying twins.     

What is your diagnosis? Intracranial mass in a cat

Abstract: A 14‐year‐old female spayed cat was presented with a 3–4‐month history of circling to the left and intermittent head pressing. Neurologic examination findings localized the lesion to the left supratentorial region. Using magnetic resonance imaging, an extra‐axial mass was found on the dorsal aspect of the brain at the level of the frontal and parietal lobes, compressing and displacing the brain ventrally and caudally. Craniectomy was performed and the mass was submitted for cytologic and histopathologic evaluation. Impression smears revealed abundant cholesterol crystals and loose clusters of mildly pleomorphic spindle cells, compatible with a meningioma. The histopathologic diagnosis was meningioma with psammoma bodies and numerous cholesterol clefts. Abundant cholesterol crystals within meningiomas in cats may present a diagnostic challenge when nucleated cells are scant. Other differential diagnoses for abundant cholesterol crystals in an intracranial mass include cholesterol granulomas and keratinizing cysts.     

白灵菇菌丝体与子实体有效成分分析比较

采用原子吸收、紫外扫描以及氨基酸分析等方法对白灵菇菌丝体和子实体的营养成分进行测定分析。结果表明：白灵菇菌丝体和子实体可溶性物质、可溶性蛋白、总糖、还原糖、氨基态氮含量相近;菌丝体与子实体紫外扫描峰形基本相似;氨基酸的组成一致,并且都含有人体必需的8种氨基酸,且菌丝体中的氨基酸含量明显高于子实体。     

超声波处理对文心兰类原球茎增殖及分化的影响

采用不同频率不同时间超声波处理文心兰类原球茎（OLBs）和无菌苗，以探讨适宜的类原球茎增殖、分化及生根条件，结果表明：25kHz超声波处理组PLBs平均增殖率比40kHz超声波处理组高23．4％，其中25kHz超声波处理3min促进PLBs增殖效果较佳，PLBs平均增殖率比对照高49．5％；25kHz超声波处理组PLBs平均分化芽数比40kHz超声波处理组高28．3％，其中25kHz超声波处理6min促进分化效果较佳，平均分化芽数比对照高98．8％，25kHz超声波处理组无菌苗平均根长与平均根数比40kHz处理组高10．1％和13．6％，其中25kHz超声波处理3min促进生根效果较佳，无菌苗平均根长与平均根数比对照组高75．0％和37．5％。     

秋石斛同源四倍体诱导与鉴定

 为了创制秋石斛同源四倍体新种质, 以秋石斛同株异花授粉种子为材料, 用组织培养方法,通过种子非共生萌发与原球茎诱导, 在原球茎发育的原胚期, 以低浓度混合诱变剂进行多倍体诱导。结果用0.01%秋水仙素+ 5 mg·L ^{- 1}氨磺灵处理8～10 d, 四倍体(2n = 4X = 76) 诱变率达90%以上, 未发现嵌合体。与二倍体对照比较, 四倍体植株粗壮, 叶色深绿, 叶片宽厚。     

水稻胚乳细胞发育中的蛋白体的形成

用透射电子显微镜观察了水稻胚乳细胞发育中蛋白体的形成. 花后5天, 胚乳细胞粗面内质网(RER)数量迅速扩增, 蛋白体开始形成. 蛋白质在RER上合成后, 分别以不同的方式积累在RER和液泡中, 形成蛋白体Ⅰ和蛋白体Ⅱ. RER槽库膨大积累蛋白质和形成环状RER积累蛋白质是形成蛋白体Ⅰ的主要方式; 在内表面积累有蛋白质的大液泡出芽和     

濒危动物遗传资源的保存

随着生物技术、分子生物学、基因工程理论和技术的日臻完善,使得濒危动物遗传资源的长期保存成为现实。动物遗传资源保存方法多种多样,如活体保种、干细胞库、突变体库、生殖细胞库、cDNA文库、基因组文库等。阐述了活体、生殖细胞、胚胎、体细胞、基因组文库的保存方法、影响因素、研究进展、以及发展前景等。各种保存方式各有利弊,要针对不同的物种采取不同的保存方法;多层面、立体化保存是动物遗传资源保存最理想的方式。     

金钗石斛类原球茎诱导及增殖的正交试验

通过正交试验,筛选了金钗石斛Dendrobiumnobile类原球茎(protocrom likebodies,PLBs)诱导及增殖适宜的培养基.以1/2MS附加8g·L-1琼脂为基本培养基,诱导以NAA、TDZ(噻二唑苯基脲,thidiazuron)、CPPU[N(2氯4吡啶基)N1苯脲]做三因子四水平试验,增殖则以NAA、BA、蔗糖、pH值做四因子四水平试验,根据L16(45)正交表设计,分别以PLBs诱导率和增质量率为指标,筛选了适宜于PLBs诱导和增殖的培养基.结果显示:1/2MS+30g·L-1蔗糖+8g·L-1琼脂+0.01mg·L-1TDZ+0.005mg·L-1CPPU,pH5.6的培养基适宜于PLBs诱导,1/2MS+20g·L-1蔗糖+8g·L-1琼脂+20g·L-1香蕉汁+1.0mg·L-1NAA+0.2mg·L-1BA,pH5.6的培养基增殖效果较好;诱导率和增质量率分别为46.00%和756.74%.在各因子中,NAA对PLBs诱导率的影响最大,并对PLBs的诱导起抑制作用;蔗糖质量浓度对PLBs增质量率影响最大,且较低的质量浓度更为适宜;筛选出的PLBs诱导和增殖培养基经重复试验,结果相对稳定.     

文心兰类原球茎形态建成及电子传递蛋白和凯氏带蛋白基因的极性表达模式分析

以文心兰‘柠檬绿’（Oncidium hybridum ‘Honey Angel’）为材料进行类原球茎发育过程的形态和结构观察,对其离体形态建成进行分析,并对类原球茎（protocorm-like body, PLB）分化过程中的顶部和基部组织以及组培苗的根、茎、叶中的凯氏带蛋白基因CASP和电子传递蛋白基因Fd（ferredoxin）、FNR（ferredoxin-NADP⁺oxidoreductase）的表达模式进行分析。结果显示：类原球茎在分化过程中逐步建立了两极性。随着类原球茎的发育,自顶端向基部形成维管形成层,继而形成维管束;之后有叶原基产生并形成单子叶式茎尖结构和出现类原球茎胚轴的伸长,无胚根形成。类原球茎形成幼苗后植株基部有侧根的产生。实时荧光定量PCR结果表明：在根中高表达和在茎中高表达的CASP、FNR和Fd基因在类原球茎不同发育阶段和组织中存在极性的差异表达,参与了无胚根体细胞胚胎的生长发育过程。综上所述,文心兰体细胞胚在发育过程中从弱分化器官向茎叶器官转变,形成兰花特有的非同步体细胞胚胎发育现象——类原球茎。     

提高金针菇锌含量的研究

对培养基质添加ＺｎＳＯ＿４，研究了锌对金针菇菌丝生长及子实体发育的影响。结果表明，在固体培养基质中添加５０～４００ｍｇ／ｋｇ锌，菌丝生长正常，能提早形成子实体原基，提高早期产量。当添加量超过１ｇ／ｋｇ时，菌丝和子实体的生长发育均受到影响。添加５０～３０００ｍｇ／ｋｇ时，子实体干样含锌为０．３７～０．７９ｍｇ／ｇ，比对照高７．４～１５．８倍。