桑树桑黄子实体和发酵菌粉有效成分分析

对桑树桑黄的子实体和发酵菌粉的氨基酸、矿物质元素以及多糖等主要活性成分的含量进行了分析比较。结果表明,桑树桑黄子实体和发酵菌粉均含有17种氨基酸,均以谷氨酸含量最高,必须氨基酸中都以亮氨酸含量最高。桑树桑黄子实体和发酵菌粉中都含有人体必不可少的钙、铁、锌等8种矿物质元素。桑树桑黄发酵菌粉多糖、黄酮含量均高于子实体。桑树桑黄发酵菌粉黄酮含量为3.97%,多糖含量为12.8%;子实体黄酮含量为0.1%,多糖含量为4.76%。     

桑黄多糖抗疲劳及耐缺氧实验研究

研究采用水提醇沉法得到桑黄菌丝多糖(大分子量粗多糖),通过小鼠抗疲劳、耐缺氧能力实验,研究桑黄菌丝多糖的生理活性。以小鼠游泳力竭时间、游泳前后血乳酸、肝糖原以及血清尿素氮含量的变化为指标,考察桑黄多糖抗疲劳能力,以小鼠在缺氧和亚硝酸钠中毒环境下的存活时间为指标,考察桑黄多糖耐缺氧能力。结果表明,灌胃桑黄多糖可以显著延长小鼠游泳时间达70.62%,降低游泳后乳酸曲线下面积22.89%,提高肝糖原储备33.36%,减少游泳后血清尿素氮含量23.17%,延长小鼠在缺氧环境下42.08%和亚硝酸钠中毒环境下35.29%的存活时间。因此,桑黄多糖具有提高小鼠抗疲劳和耐缺氧能力的作用,且在一定剂量范围内,实验效果与灌胃剂量呈正效应关系。     

秋水仙素诱变对桑黄菌丝生长及活性成分的影响

以1.0%纤维素酶和0.5%蜗牛酶不同处理时间的桑黄菌丝为试材,采用0.1%秋水仙素诱变桑黄菌丝研究其诱变下桑黄菌丝再生菌株的生长速率以及多糖、黄酮和三萜等活性成分含量变化,以期获得生长快且活性成分含量高的菌种,以期为桑黄菌株选育、种质资源创新和应用奠定基础。结果表明:秋水仙素诱变后桑黄菌丝再生菌株的生长速率以及多糖、黄酮和三萜等活性成分含量基本呈增加趋势。其中,与对照相比,诱变酶解桑黄菌丝20 min获得的再生菌株20-1生长速率最快,增加了366.67%;三萜和多糖含量最高的再生菌株为10-5,分别增加了1069.73%和281.85%;多酚含量最高的再生菌株为5-1,增加了530.56%;黄酮含量最高的再生菌株为30-1,增加了3771.43%。     

桑黄的研究进展

桑黄是一种珍贵的药用真菌，本文介绍了桑黄的药用功能、深层发酵、桑黄多糖的提取纯化工艺以及桑黄多糖的分子组成和结构。     

桑黄多糖的研究进展

桑黄(Phellinus)是国际公认抗癌效果较好的大型药用真菌之一,桑黄代谢产生的多糖具有明显的抑制肿瘤和提高机体免疫力的功效,为当前新型抗癌药物研究领域的热点。就桑黄多糖的化学结构、提取纯化方式及其药理作用进行了综述,并总结了桑黄多糖的产品开发情况,旨在为开发桑黄功能保健品和药品提供理论依据。     

四种桑黄的培养特性及主要活性成分的比较分析

以金桑黄JS1、龙桑黄LS2、杨桑黄YS3和桑黄S6 4种桑黄菌种为试材，采用紫外比色法比较不同桑黄子实体中总三萜、总黄酮和总多糖的含量，通过对桑黄母种、原种和子实体栽培进行优选，分析不同阶段各桑黄菌丝体生长情况及子实体中活性成分的差异，以期为桑黄功能活性物质的研究及子实体品质控制提供参考依据。结果表明：不同阶段菌丝萌发速度呈显著性差异，4种桑黄母种均在以蔗糖为碳源的PDA加富培养基上生长最快，在玉米粉和麸皮培养基上生长相对缓慢，而在桑枝滤液培养基上生长最慢，YS3菌丝生长表型综合最佳。桑黄原种菌丝在第3天的生长速度均最快，JS1、YS3和S6在麸皮培养基中菌丝生长均最快，分别为4.78、4.60 mm·d^-1和3.08 mm·d^-1;LS2在4种培养基中生长速度差异不显著，其中在玉米粉培养基中最快为4.17 mm·d^-1。对比分析不同桑黄子实体活性成分含量，LS2子实体多糖含量最高，YS3子实体总黄酮和三萜含量最高，S6子实体黄酮、三萜及多糖含量均最低。综合考虑菌丝生长速度、农艺性状、子实体活性成分含量，桑黄YS3和L...     

桑黄菌丝固体培养基筛选研究

将桑黄菌种分别接种于不同成分培养基上进行培养,以桑黄菌丝体生物量、粗多糖产量和黄酮产量为指标,筛选出桑黄菌丝培养最适培养基.采用苯酚一硫酸法测定粗多糖含量、UV法测定总黄酮含量.最终结果表明桑黄固体培养基的最优组合:玉米粉70％,豆粕28％,蔗糖2％,KH2PO40.1％,K2HPO4 0.1％,VB10.01％,料液比1∶1.8.     

部分稀土元素对桑黄液体发酵的影响

研究了5种稀土元素（镧、铈、钕、镨、铒）对桑黄液体发酵的影响。实验结果表明,不同的稀土元素在适宜浓度时对桑黄生物量以及多糖、三萜和黄酮等活性物质的合成,均具有一定的促进作用。其中稀土元素铈和铒有利于桑黄生物量的积累,并分别在浓度0.01 mmol.L-1和0.1 mmol.L-1时使生物量达到最大值（5.85±0.14）g.L-1和（5.34±0.45）g.L-1,比对照提高了23%和13%。而稀土元素铈、钕和镧则对桑黄胞外多糖、胞内多糖和胞内三萜的合成具有明显促进作用,其中铈在浓度0.01 mmol.L-1、钕在浓度0.1 mmol.L-1、铈在0.01 mmol.L-1时分别使胞外多糖、胞内多糖和胞内三萜产量达到最大值（610.36±0.31）mg.L-1、（789.09±2.09）mg.L-1和（106.70±2.92）mg.L-1。本文所考察的5种稀土元素都在一定程度上促进了桑黄胞外三萜和黄酮的合成,但稀土元素镧、钕和镨对胞外三萜诱导效果相对较好,而钕、铒和铈则对黄酮诱导效果相对较好。综合来看,稀土元素对桑黄液体发酵的影响,与稀土元素的种类和浓度密切相关,体现出一定的选择性和特异性。     

桑黄活性物质研究现状

近年来珍稀药用真菌桑黄(Pellinus igniarius)引起很多科研者的广泛关注,所含有的生物活性成分如多糖、黄酮、萜类化合物等在抗肿瘤、抑菌、抗氧化等方面具有非常明显的功效。桑黄的各类产品如子实体、菌丝体粉和桑黄针剂等在市场上供不应求,表明桑黄有很广阔的发展前景。以近年来国内发表的文献为依据,从桑黄形态特征、活性物质的产生规律和生物学生长特性等方面综述近年来的研究进展。     

不同提取方法对桑黄胞内多糖理化性质的影响

采用不同方法提取桑黄(Phellinus igniarius)菌丝体粗多糖,超声辅助法提取粗多糖的得率最低,但多糖含量最高。复合酶法的粗多糖得率最高,但多糖含量低。单糖组成分析表明:不同提取方法得到粗多糖的单糖组成不同;复合酶法得到的粗多糖由鼠李糖、阿拉伯糖、木糖、甘露糖、半乳糖以及葡萄糖组成;超声辅助法得到的样品由甘露糖和葡萄糖组成;热水法得到的样品由木糖、甘露糖、半乳糖和葡萄糖组成,其中葡萄糖含量比其它两种粗多糖样品高。红外和电镜扫描分析表明:不同提取法得到的桑黄粗多糖结构和形态各有差异。     

Relationship between renal hypertension and cardiac α1-adrenoceptor autoantibodies in rats

AIM: To examine the autoantibody against α₁-adrenoceptor and its biologic activities during the development of renal hypertension. METHODS: Renal hypertension of rat was achieved by clipped renal artery, the titre of autoantibody to α₁-adrenoceptor was detected using ELISA immunoassay. Furthermore, the biological offects of these autoantibodies on cultured cardiomyocytes were also examined. RESULTS: After two weeks of clipping renal arteries, both the frequency of occurrence and the titre of autoantibodies to cardiac α₁-adrenergic receptor were significantly increased as compared with the control of pre-treatment. The increased autoantibodies lasted for several weeks and then automatically decreased gradually to the pre-clipping level at 12 weeks. The biological effects of these autoantibodies displayed an "agonistic-like" activities on the beating frequency of cultured neonatal cardiomyocytes. CONCLUSION: Autoantibodies against α₁-adrenoceptor may play a role in the elevation of peripheral vascular resistance and in the development of cardiac hypertrophy in rats with renal hypertension.     

Effects of radiation from 188Re on smooth muscle cell proliferation

AIM: Although endovascular radiotherapy inhibits neointimal hyperplasia, the exact alterations induced by β-particles irradiation remain to be elucidated. The objective of this study was to investigate the ability and the cellular mechanism of local β^-particles emission from ¹⁸⁸Re to inhibit vascular smooth muscle cells (SMCs). METHODS: The SMCs in vitro were irradiated by ¹⁸⁸Re with single doses of 2.6 Gy-25.8 Gy. The effects of β-particles on SMCs, such as effective irradiate doses, the period of inhibition for SMCs proliferation, the changes of cell proliferation rate and DNA synthesis rate, cell cycle progression and related gene expression, were investigated by cell count, [³H]-TdR incorporation, cell cycle progression analysis, cell viability and immunocytochemistry, respectivecy. RESULTS: β-particles irradiation with dose of 5.2 Gy could inhibit significantly SMCs proliferation. At dose of 20.6 Gy DNA synthesis inhibitory rate was 92%, SMCs proliferation rate was only 3%. Renoval of ¹⁸⁸Re did not abolish the inhibitory effects of β-particles on SMCs proliferation. The expression of P53 was up regulation and PCNA was down regulation after irradiation. CONCLUSION: β-particles from ¹⁸⁸ Re was significantly effective and permanent in inhibiting SMCs proliferation, and inhibitory effect was in dose-dependet manner ED50was 5 Gy, the best dose to inhibit SMCs proliferation was 20 Gy. β-particles irradiation induced SMCs to occur G₀/G₁ arrest, damaged the ability of SMCs reproliferation and led to cell clonogenic death. P53 and PCNA had regulatiory effects on SMCs proliferation after β-particles irradiation.     

Influence of Mineral Nutrients on Strawberry Fruit Quality and Their Accumulation in Plant Organs

Abstract

This review is based partly on complete articles and partly on abstracts. Three of the 60 articles deal with the total uptake of elements in strawberry plant organs in two different strawberry production systems, both considered as optimal concerning amount and balance of elements. The effect on fruit quality may be dramatic if the level of a particular element is outside this range, but there may also be effects initiated by differences within the optimal range of elements. Most articles refer to product oriented quality, but some focus on consumer oriented quality, as discussed by Shewfelt (1999). The discussion here is on a general basis, so one should keep in mind that there are cultivar differences and that specification of nutrition ideally should mirror the needs of a single cultivar, or a group of cultivars with similar requirements. Also, to get a complete understanding of the subject future reviews should embrace a broader access of information including the effect on plant development of individual elements, such as the role of calcium in fruit firmness and its importance in cell wall structure. However, the intention here is to narrow the information to results that suggest a direct connection between nutrient uptake and fruit quality.     

Effect of L-Arg on plasma content of endothelin and expression of c-fos mRNA in the left ventricle of rats with renovascular hypertensive hypertrophy

AIM:To study the effect of L-Arg on plasma content of endothelin (ET) and the expression of proto-oncogene c-fos mRNA in the left ventricle of rats with renovascular hypertensive hypertrophy. METHODS: The level of c-fos mRNA were measured by in situ hybridization. The ET in plasma were measured by radioimmunoassay. RESULTS:After eight weeks of treatment with L-Arg, the expression of c-fos decreased markedly (P＜0.01). The ET content in plasma also decreased significantly by L-Arg(P＜0.01).CONCLUSION: Plasma ET content and the expression of c-fos in the left ventricle of rats with renovascular hypertensive hypertrophy could be decreased by L-Arg administration.     

Mixed-severity fire regime in a high-elevation forest of Grand Canyon,Arizona, USA

Fire regime characteristics of high-elevation forests on the North Rim of the Grand Canyon, Arizona, were reconstructed from fire scar analysis, remote sensing, tree age, and forest structure measurements, a first attempt at detailed reconstruction of the transition from surface to stand-replacing fire patterns in the Southwest. Tree densities and fire-/non-fire-initiated groups were highly mixed over the landscape, so distinct fire-created stands could not be delineated from satellite imagery or the oldest available aerial photos. Surface fires were common from 1700 to 1879 in the 4,400 ha site, especially on S and W aspects. Fire dates frequently coincided with fire dates measured at study sites at lower elevation, suggesting that pre-1880 fire sizes may have been very large. Large fires, those scarring 25% or more of the sample trees, were relatively infrequent, averaging 31 years between burns. Four of the five major regional fire years occurred in the 1700s, followed by a 94-year gap until 1879. Fires typically occurred in significantly dry years (Palmer Drought Stress Index), with severe drought in major regional fire years. Currently the forest is predominantly spruce-fir, mixed conifer, and aspen. In contrast, dendroecological reconstruction of past forest structure showed that the forest in 1880 was very open, corresponding closely with historical (1910) accounts of severe fires leaving partially denuded landscapes. Age structure and species composition were used to classify sampling points into fire-initiated and non-fire-initiated groups. Tree groups on nearly 60% of the plots were fire-initiated; the oldest such groups appeared to have originated after severe fires in 1782 or 1785. In 1880, all fire-initiated groups were less than 100 years old and nearly 25% of the groups were less than 20 years old. Non-fire-initiated groups were significantly older (oldest 262 years in 1880), dominated by ponderosa pine, Douglas-fir, or white fir, and occurred preferentially on S and W slopes. The mixed-severity fire regime, transitioning from lower-elevation surface fires to mixed surface and stand-replacing fire at higher elevations, appeared not to have been stable over the temporal and spatial scales of this study. Information about historical fire regime and forest structure is valuable for managers but the information is probably less specific and stable for high-elevation forests than for low-elevation ponderosa pine forests.This revised version was published online in May 2005 with corrections to the Cover Date.     

Compositional and Functional Properties of Saskatoon Berry and Blueberry

Abstract

Saskatoon berry (Amelanchier alnifolia Nutt., Rosaceae) and blueberry (Vaccinium corymbosum L., Ericaceae) are substantially equivalent in all characteristics that are important to the consumer, including fruit color, shape, size, nutrition, texture, and uses. In addition, both fruits are native to North America and they have practically identical historical uses and known health benefits. Their composition, processing, nutritional value and metabolism, intended uses, and levels of undesirable substances are compared.     

Cryopreservation of shoot apices of hawthorn in vitro cultures originating from East Asia

The objective of this study was to establish a cryopreservation protocol for hawthorn shoot apices (Crataegus pinnatifida Bge.). Cryopreservation was carried out via encapsulation–dehydration, vitrification, and encapsulation–vitrification on shoot apices excised from in vitro cultures. We began by showing that cold-acclimation enhanced the regrowth of cryopreserved apices from 10.0 to 65.5% in encapsulation–dehydration. We then decided that the encapsulation–dehydration method was an optimal cryopreservation method for hawthorn shoot apices in terms of its high recovery after cryopreservation as well as its ease of use compared with vitrification and encapsulation–vitrification. In encapsulation–dehydration, the protocol leading to optimal regrowth was as follows: after cold-acclimation at 5 °C in the dark for 2 weeks, excised shoot tips were pretreated for 24 h at 25 °C on hormone-free Murashige and Skoog [Murashige, T., Skoog, F., 1962. A revised medium for rapid growth and bioassays with tobacco tissue culture. Physiol. Plant. 15, 473–497] (MS) basal medium with 0.4 mol/L sucrose, then encapsulated and precultured in liquid MS medium with 0.8 mol/L sucrose for 16 h at 25 °C. Precultured beads were dehydrated for 6 h at 25 °C in the dessicator containing 50 g silica gel to a moisture content of 15.3% (fresh-weight basis) before cryostorage for 1 h. In addition, we examined the effect of adding glycerol to both the alginate beads and loading solution to enhance regrowth after cryopreservation in encapsulation–dehydration. In the present study, it was shown that adding 0.5 mol/L glycerol resulted in high regrowth percentages (82.5–90.0%) in four Crataegus species.     

瓜叶绿素降解关键酶基因PPH和PAO cDNA片段的克隆与表达初步分析

 以西双版纳黄瓜和‘华黄5号’黄瓜叶片为试验材料,研究了衰老过程中两种黄瓜叶片叶绿素含量变化及脱镁叶绿素脱镁叶绿酸水解酶基因PPH和脱镁叶绿酸a加氧酶基因PAO的表达。结果表明：随着叶片衰老,叶绿素a和叶绿素b含量显著降低,叶绿素a与叶绿素b的比值在0.5左右,推测叶绿素b的含量可能对黄瓜叶片保绿起到重要作用。荧光定量RT-PCR分析结果显示：PPH和PAO在西双版纳黄瓜叶片生长35 d时表达量最高,分别为5.50和1.86;PPH在‘华黄5号’叶片35 d时表达量最高,为7.14,而PAO在35和45 d表达量都很高,分别为3.90和3.91;PPH和PAO在西双版纳黄瓜叶片中的表达量低于在‘华黄5号’中。     

Effects of simvastatin on PDGF-BB and serum-induced proliferation of vascular smooth muscle cells and on the expression of tumor suppressor gene PTEN

AIM:To observe the effect of simvastatin on the proliferation of vascular smooth muscle cells(VSMCs) induced by serum and growth factor PDGF-BB and the effect of simvastatin on the expression of PTEN,a important regulator of G₁/S cell cycle transition. METHODS:The DNA synthesis was determined by [³H]-TdR incorporation, cell cycle was examined with flow cytometry, the protein level of PTEN was measured by Western blot method. RESULTS: (1)Simvastatin inhibited [³H]-TdR incorporation in a dose dependent manner. (2) Flow cytometric DNA analysis revealed that simvastatin induced significantly enhancement of G₀/G₁ phase and decrease in S phase VSMCs.(3)Simvastatin increased protein level of PTEN and mevalonate, a metabolite of HMG-COA, reversed the effect of simvastatin on PTEN protein expression. CONCLUSION:Simvastatin may inhibit proliferation of VSMCs and retarded cell cycle in G₀/G₁ phase by increasing PTEN expression through inhibiting synthesis of mevalonate.     

Relationships of landscape,prey and agronomic variables to the abundance of generalist predators in cotton (<Emphasis Type="Italic">Gossypium hirsutum</Emphasis>) fields

A two-year field study investigated the possible effects of grain sorghum (Sorghum bicolor [L.] Moench) and uncultivated areas on the abundance of generalist predators in commercially-managed cotton (Gossypium hirsutum L.) fields in Texas, USA. From 63 to 70 fields were sampled for pests and predators over nine consecutive weeks during early stages of cotton development. Additional data on agronomic practices and landscape composition at three spatial scales were also collected for each field. Stepwise regression analyses were used to determine the relationships of landscape, agronomic and prey variables to the abundance of generalist predators. Because the variables most closely linked to predator levels could vary over time, separate regressions were conducted for three time periods corresponding to stages of grain sorghum growth (half-bloom, hard-dough, maturity) in each year. Significant relationships between predator abundance and agricultural landscape composition appear in both years and in all three time periods, but the specific relationships of landscape variables to cotton predator levels differed between and within years. At maturity in 2001, predator levels rose as the amount of uncultivated land from 1.6 to 3.2 km distant and the perimeter shared with grain sorghum increased. During 2002, the area of grain sorghum (half-bloom) and uncultivated land (hard-dough) within 1.6 km of cotton fields were both positively related to predator numbers. Cotton planting dates and the abundance of cotton fleahoppers (Pseudatomoscelis seriatus [Reuter]) were also strongly linked to predator numbers during both years. Results suggest that the total amount of grain sorghum or uncultivated land in an area is more important than the presence of these habitats adjacent to cotton fields, and that landscape composition may sometimes be the most important factor in determining predator abundance.