Vitamin D Status in Different Stages of Disease Severity in Dogs with Chronic Valvular Heart Disease

Background

In humans with heart disease, vitamin D deficiency is associated with disease progression and a poor prognosis. A recent study showed that serum 25‐hydroxyvitamin D [25(OH)D] concentration, the hallmark of vitamin D status, was lower in dogs with heart failure than in normal dogs, and a low concentration was associated with poor outcome in dogs with heart failure.

Objectives

To elucidate the vitamin D status of dogs with chronic valvular heart disease (CVHD) at different stages of disease severity.

Animals

Forty‐three client‐owned dogs with CVHD.

Methods

In this cross‐sectional study, dogs were divided into 3 groups (14 dogs in Stage B1, 17 dogs in Stage B2, and 12 dogs in Stage C/D) according to ACVIM guidelines. Dogs underwent clinical examination including echocardiography. Serum 25(OH)D concentrations were measured in each dog.

Results

Serum 25(OH)D concentration was significantly lower in Stage B2 (median, 33.2 nmol/L; range, 4.9–171.7 nmol/L) and C/D (13.1 nmol/L; 4.9–58.1 nmol/L) than in Stage B1 (52.5 nmol/L; 33.5–178.0 nmol/L) and was not significantly different between Stage B2 and Stage C/D. Among clinical variables, there were significant negative correlations between 25(OH)D concentration and both left atrial‐to‐aortic root ratio and left ventricular end‐diastolic diameter normalized for body weight.

Conclusions and Clinical Importance

These results indicate that vitamin D status is associated with the degree of cardiac remodeling, and the serum 25(OH)D concentration begins to decrease before the onset of heart failure in dogs with CVHD.     

Effects of RNA interference targeting CDC25agene on proliferation of human liver cancer HepG2 cells

AIM: To investigate the effect of silencing cell division cycle 25a (CDC25a) gene on the proliferation of human hepatoma HepG2 cells. METHODS: CDC25agene in human hepatoma HepG2 cells was silenced by RNA interference. Real-time PCR was applied to detect the expression of CDC25a, cyclin E and CDK2 at mRNA levels in the HepG2 cells. Western blotting was applied to detect the expression of CDC25a at protein level. In addition, MTT assay, Giemsa staining and flow cytometry were used to measure the proliferation of human hepatoma HepG2 cells. RESULTS: The expression of CDC25a at mRNA and protein levels in RNA silence group was lower than those in negative control group and normal control group (P＜0.05). The mRNA expression of cyclin E and CDK2 in silence group was lower than that in negative control group and normal control group (P＜0.05). The cell proliferation in silence group was lower than that in negative control group and normal control group (P＜0.05). The results of flow cytometry revealed that the cells in silence group were blocked in G1 phase. CONCLUSION: Infection of LV-CDC25a-RNAi recombinant to the HepG2 cells effectively inhibits the CDC25agene expression and the proliferation of human hepatoma cells, and arrests the cells in G1 phase, suggesting that CDC25agene may be a key target for the treatment of liver cancer.     

Temporal changes in plasma thyroid hormone,growth hormone and free fatty acid concentrations,and hepatic 5′-monodeiodinase activity,lipid and protein content during chronic fasting and re-feeding in rainbow trout (Oncorhynchus mykiss)

Temporal changes in growth, plasma thyroid hormone, cortisol, growth hormone (GH) and non-esterified fatty acid (NEFA) concentrations, hepatic T₃ content and hepatic 5-monodeiodinase activity were measured in rainbow trout (Oncorhynchus mykiss) subjected to a sustained fast for up to eight weeks, and during a four-week re-feeding period. The purpose of the study was to examine aspects of the endocrine control of energy partitioning processes characteristic of short-term (acute; fasting) and long-term (chronic; starvation) food-deprivation states in fish, and to explore the role of the thyroid hormones, cortisol and GH in the energy repartitioning that takes place during an acute anabolic (re-feeding) state following chronic food deprivation.Differences in growth rate between fed and fasted groups were evident after two weeks, but significant weight loss by the fasted groups was not evident until between four and six weeks into the fast. Hepatosomatic indices (HSIs) were significantly reduced in the fasted fish within seven days, and as early as two days in one study; recovery of the HSI in fasted fish was evident within three days of re-feeding. Liver protein content (expressed as % wet weight) was consistently depressed in the fasted fish in only one of the three studies. Liver total lipid content (expressed as % wet weight) was depressed in the fasted fish within two days of food deprivation. Because of the rapid and sustained decrease in the HSI of fasted fish, the hepatic total protein and lipid reserves, when considered on a body weight basis, were markedly lowered within the first few days of the fast. Plasma GH concentrations exhibited a bi-modal pattern of change, with a transient fall in levels, followed by a sustained increase in fasted fish. The indicators of interrenal activity were suggestive of a depressed pituitary-interrenal axis in fasted animals; plasma cortisol levels were elevated to levels of fed animals within one day of re-feeding. The indicators of thyroid hormone economy (plasma thyroid hormone levels, liver triiodothyronine content, hepatic 5-monodeiodinase (MD) activity, thyroid epithelial cell height) were similarly indicative of a depressed pituitary-thyroid axis in fasted animals, with recovery to levels of the fed animals within one week. Despite the compensatory changes in accumulation of reserves (as indicated by a compensatory increase in HSI), there were no apparent compensatory changes in any of the endocrine parameters evident during the re-feeding period.     

纤维素降解真菌A25-2的分离、鉴定及其产纤维素酶的酶学特性

本研究以Avicel-刚果红选择培养基为初筛培养基,从云南哀牢山国家级自然保护区和广西猫儿山国家级自然保护区的土壤样品中分离筛选得到4200株真菌,从中筛选出透明圈与菌落直径比较大、透明程度较为清晰的12个菌株。通过液体培养发酵,测定其上清液中的羧甲基纤维素酶活力、滤纸酶活力和Avicel酶活力,最终筛选出一株产该三种酶且其活力均最高的真菌菌株A25-2。通过对菌株A25-2形态学观察和其内转录间隔区（internal transcribed spacer,ITS）序列同源性比对分析,将菌株A25-2鉴定为哈茨木霉（Hypocrea lixii）。酶活测定结果表明菌株A25-2产纤维素酶的酶活力较高,在最适作用pH4.5和最适作用温度55℃下,其羧甲基纤维素酶活力为2.26IU/mL,滤纸酶活力为0.58IU/mL,Avicel酶活力为0.39IU/mL。薄层层析实验表明A25-2具有完整的纤维素酶系统。因此,真菌A25-2可作为饲料加工等生产和纤维素酶相关研究的备选菌株。     

忆晋西一次修成水平梯田的产生和兴起

忆晋西一次修成水平梯田的产生和兴起刘足征（湖南省水电厅，长沙市４１０６０７）在晋西吕梁山区以至黄河中游广大山区，现在到处可以见到层层叠叠的一次修成的水平梯田。面对这一雄伟壮观，令人心情舒畅，不禁回想到４０年以前的景象。那时，在这片黄土高原广大山区，从...     

Effect of molecular complexity and acidity of earthworm faeces humic fractions on glutamate dehydrogenase,glutamine synthetase,and phosphoenolpyruvate carboxylase in Daucus carota α II cells

Carrot cells were grown in cultures supplemented with two hormones [2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzylaminopurine (6BAP)] and two humic fractions extracted from earthworm faeces, one with high acidity and a low apparent molecular size (<3500) and the other with low acidity and a large molecular size. 2,4-D stimulated growth through an effect on cell enlargement, while the strongly acidic humic fraction (0.2 mg l^-1) and the weakly acidic fraction (1 mg l^-1) were both less effective. With 4–16 h of pre-incubation, the highly acid humic fraction, mainly alone, induced the best increase in protein content; the effect of the weakly acid humic fraction and the hormones was generally less important. The two humic fractions also differed in their influence on glutamate dehydrogenase activity. After 2 h of pretreatment, the highly acidic fraction increased glutamate dehydrogenase activity, while the other fraction did not affect it. After 4–16 h of pre-incubation, the activity of this enzyme was still not influenced by these humic fractions. The presence of the two hormones did not interfere with the humic matter effects. Glutamine synthetase activity was not affected by a pre-incubation of up to 4 h with the two humic fractions, but it was stimulated after 8–16 h of pre-incubation. A 2,4-D+6BAP mixture stimulated glutamine synthetase activity (from +12 to +50%). Again, the presence of the hormones did not interfere with the effects induced by the humic fractions. After 16 h of pre-incubation, phosphoenolpyruvate carboxylase activity was increased by the highly acidic humic fraction (+93%) and by both humic fractions together (+34%). An explanation of the different incubation times necessary for the humic fractions to exert stimulatory effects on these enzymes is proposed here. The regulatory properties of the strongly acidic humic fraction appeared to depend on the combination of high acidity (expecially carboxylic C) with low molecular size.     

吉林省东部半山区“四密25”玉米产量构成因素的浅析

四密25是优质高产适应性较强的玉米品种,虽创造出吉林省东部半山区15000kg/hm2的高产记录,但产量波动(7500～15000kg/hm2)较大。为进一步研究其高产稳产的构成因素,1994-2004年,在吉林省东部半山区桦甸市5个乡镇,应用四密25分别进行了品种比较、高产攻关、覆膜种植与裸地种植、不同施肥量、施肥方法、播种方法、播种时期、不同密度及等离子体处理种子的剂量、次数、播种期、化肥利用率的试验。通过对上述各项试验的194份材料统计分析,明确了四密25构成产量模型的3个主导因素为千粒重、穗粒数、公顷穗数。根据回归分析理论,计算出产量与3个主导因素之间的模型,为今后吉林省东部半山区四密25高产稳产提供理论依据。     

25%阿米西达悬浮剂与6种药剂混用对辣椒安全性的影响

用新型高效低毒仿生杀菌剂25%阿米西达悬浮剂与生产上常用的6种杀虫剂和杀菌剂设计成7个混用组合,于不同辣椒品种的不同生育期实施叶面喷雾,结果显示,所有混用组合均不会对辣椒的株高和叶片数量造成不良影响,辣椒植株上也未观察到任何药害症状,从而确认了其在辣椒上应用的安全性.     

海岛棉GbMYB25基因的克隆及表达分析

根据陆地棉GhMYB25的序列,设计1对引物,通过RT-PCR技术从海岛棉品种新海21号中克隆了1个同源基因,命名为GbMYB25。GbMYB25基因具有1个930bp的开放阅读框,编码309个氨基酸,预测分子量约为34.762ku,等电点为8.08,推测的氨基酸序列中含有2个高度保守的SANT结构域。GbMYB25基因序列包含2个内含子。氨基酸序列比对表明,该蛋白和其他高等植物的MYB蛋白有较高的同源性。进化树分析表明,GbMYB25基因和陆地棉GhMYB25基因处在同一进化树分支。亚细胞定位表明GbMYB25基因在细胞核中表达,实时荧光定量PCR结果表明GbMYB25基因在胚珠(0doa)、纤维(5dpa)和叶片中的表达量较高。以上结果表明,GbMYB25转录因子可能参与棉花纤维发育。     

25%维特美克EC、爱益农EC防治水稻中后期病害对比试验

筛选出防治水稻中后期病害的最佳药剂,特选用25%维特美克EC和爱益农EC与常规药剂进行对比试验。结果表明:25%维特美克EC对水稻中后期病害的防治效果较好,产量为7 773.3 kg/667 m2,增产率达6.97%。