Structural and ultrastructural alterations of Malpighian tubules of Anticarsia gemmatalis (Hübner) (Lepidoptera: Noctuidae) larvae infected with different Anticarsia gemmatalis multiple nucleopolyhedrovirus (AgMNPV) recombinant viruses

Malpighian tubules constitute the main excretion organ of insects. Infection by egt⁻ recombinant AcMNPV baculovirus in lepidopteran larvae promotes early degeneration of these structures, which has been correlated with earlier death of the host. However, no trace of viral infection has been detected in that tissue. We constructed two AgMNPV recombinants with the egfp gene under control of the hsp70 promoter, one being egt⁻, and used another two recombinants (one egt⁻) containing the lacZ gene. Morphological alterations in the tubules were analyzed by light and electron microscopies. Bioassays were conducted to compare the pathogenicity of recombinants. Results showed progressive presence of marker proteins and tissue degeneration without signals of infection in the tissue. Morphological and bioassay results showed increased pathogenicity for lacZ-containing recombinants compared to the egfp ones; as for egt⁻ viruses, we noted higher intensity and earlier onset of alterations. The absence of infection led us to believe that Malpighian tubules degeneration is provoked initially by the death of tracheal cells attached to the tubules and later, by the death of Malpighian tubule cells themselves. Tubule cell death might be due to oncosis and apoptosis, which may be activated by depletion of energy reserves and by accumulation of marker proteins, respectively. Absence of the egt gene may be leading to a higher energetic expense due to molting, thus aggravating tubule cell death, resulting in faster death of host.     

Larval development and proteolytic activity of Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae) exposed to different soybean protease inhibitors

Anticarsia gemmatalis represents a relevant factor for lowering soybean and other legume crop productivities. Protease inhibitors affect protein degradation and reduce the availability of amino acids, impairing the development and survival of insect pests. To evaluate the possible use of proteinaceous protease inhibitors in the management of this pest, the activities of midgut proteases and the growth and development of A. gemmatalis larvae exposed to soybean Bowman–Birk trypsin-chymotrypsin inhibitor (SBBI) and soybean Kunitz trypsin inhibitor (SKTI) were determined. The survival curves obtained using Kaplan–Meier estimators indicated that SKTI and SBBI stimulated larval survival. However, the development of A. gemmatalis was delayed, and prepupal weight decreased in the presence of both inhibitors. The results showed that SKTI and SBBI inhibited the trypsin-like and total proteolytic activities of larvae on the 12th day after eclosion. On the 15th day after eclosion, larvae exposed to SKTI increased the activities of trypsin and total proteases. Although SKTI and SBBI did not affect the survival of the insect, they had effects on midgut proteases in a stage wherein A. gemmatalis fed voraciously, increased the larval cycle, and decreased prepupal weight. These findings provide baseline information about the potential of proteinaceous protease inhibitors to manage the velvetbean caterpillar, avoiding chemical pesticides.     

Temperature-Dependent Parasitism,Survival, and Longevity of Five Species of Trichogramma Westwood (Hymenoptera: Trichogrammatidae) Associated with Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae)

Egg parasitoids of the genus Trichogramma Westwood play an important role in the control of the velvetbean caterpillar Anticarisa gemmatalis Hübner in soybean crops in Southern Brazil. The effectiveness of Trichogramma species as biocontrol agents is dependent of several factors, but their adaptation to the climatic conditions of the region where they will be released is one of the most important. In this context, this study evaluated the effects of five constant temperatures ranging from 14 to 30°C on parasitism, age-specific survival, progeny production and longevity of Trichogramma pretiosum Riley, Trichogramma atopovirilia Oatman & Platner, Trichogramma acacioi Brun, Moraes & Soares, Trichogramma lasallei Pinto, and Trichogramma rojasi Nagaraja & Nagarkatti. We demonstrate that temperature differently affected the species of Trichogramma investigated when using eggs of the velvetbean caterpillar. We also demonstrate that T. pretiosum and T. atopovirilia are better adapted to a wide range of temperatures than the other species evaluated, and are therefore better suited as biocontrol agents for applied biological control programs of A. gemmatalis.     

Do different casein concentrations increase the adverse effect of rutin on the biology of Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae)?

The flavonoid rutin is recognized as playing an important role in the protection of plants against lepidopterans. Bioassays with this compound are generally carried out using artificial diets. Proteins of high energy value, such as casein, are important ingredients of insect artificial diets as a source of essential amino acids. However, such proteins can generally increase the allelochemical activity. Our objective was to evaluate the effects of rutin on larvae of the velvetbean caterpillar Anticarsia gemmatalis Hübner by incorporating this allelochemical into diets with different concentrations of casein. Three casein concentrations (0, 7 g, or 14 g) combined with none, 0.65%, or 1.30% of rutin were added to the rearing diet and offered to the larvae from hatching to pupation. Rutin negatively affected larval development, the amount of food consumed, and pupal weight of A. gemmatalis. These negative effects were clearly seen in insects fed on diets with 7 g of casein to which any concentration of rutin was added. The effects of rutin when added to the diets without casein were stronger than in diets containing a suitable amount of casein (14 g). The greater negative effects of rutin in diets containing suboptimal concentrations of casein indicate that casein can increase the effects of rutin only when the diets are nutritionally unsuitable for insect development.     

Syntheses of (±)-Epoformin (Desoxyepoxydon) and (±)-Epiepoformin (Desoxyepiepoxydon)

Boron is an essential nutrient for plants, but it is toxic in excess. Transgenic rice plants expressing an Arabidopsis thaliana borate efflux transporter gene, AtBOR4, at a low level exhibited increased tolerance to excess boron. Those lines with high levels of expression exhibited reduced growth. These findings suggest a potential of the borate transporter BOR4 for the generation of high-boron tolerant rice.     

生理卫生(下册)教学参考资料(续完)

第三节祖国在防治疾病上的伟大成就这节课是在学生已掌握了传染病的基本知識的基础上来进行講授的,首先在教材里提出以血吸虫病、天花、瘧疾、黑热病、痳疯等传染病說明了新旧社会的对比;同时也说明了社会主义社会制度的优越性。我們的党和政府对于人民健康的关怀是无微不至的,并且对于各种疾病的积极防治工作加强了党的领导,及时提出了一系列的方針、政策和措施;建立了专业防治机构,培养了专业干部;結合生产发动了广大羣众来参加防治。因此在防治各种传染病的工作中取得了很大的成績。     

生理卫生(下册)教学参考资料(续)

第五节大脑皮层的机能——高级神經活动本节是本章也是本書的高峯,是把过去学习过有关反射作用的知識进行总結和提高,使学生能从理論上理解神经对人的意义——保持內部各器官的协調,同外界环境的统一。     

稀有内养囊霉(Entrophosporainfrequens(Hall)AmesetSchneider)的研究(英)

Hall（1977）首次在新西兰的土壤中发现GlomusinjtequensHall。Ames和Schneider（979）在美国的加利福尼亚再次发现了这个种。他们认为该种与无梗囊霉（Acauloryora）有相似之处,抱子都是从泡囊发育而成,但无梗囊霉的抱于是在产抱囊的侧面形成,而该种的抱子则是在产抱囊柄的内部发育而成的。为此,Ames和Schneider（197）为这个种建立起一个新属——内养囊霉属（Entrophospora）,把这个种改名为稀有内养囊霉Entrophoworam斤equens（HallAmesetSchnelder。SChellGk和Spain（1984）报道了这个属的另一个种哥伦比亚内养囊霉（Entro…     

Structure of Poly (dT)·Poly (dA)·Poly (dT)

Abstract

The molecular structure of poly (dT)·poly (dA)·poly (dT) has been determined and refined using the continuous x-ray intensity data on layer lines in the diffraction pattern obtained from an oriented fiber of the DNA. The final R-value for the preferred structure is 0.29 significantly lower than that for plausible alternatives. The molecule forms a 12-fold right- handed triple-helix of pitch 38.4 Å and each base triplet is stabilized by a set of four Crick-Watson-Hoogsteen hydrogen bonds. The deoxyribose rings in all the three strands have C2′-endo conformations. The grooveless cylindrical shape of the triple-helix is consistent with the lack of lateral organization in the fiber.     

Robert (Robin) Hill (1899–1991)

Obituary

Robert (Robin) Hill (1899–1991)     

The Zhoukoudian (Choukoutien) Site(英汉对照)

ＴｈｅＺｈｏｕｋｏｕｄｉａｎ（Ｃｈｏｕｋｏｕｔｉｅｎ）Ｓｉｔｅ（英汉对照）ＴｈｅＺｈｏｕｋｏｕｄｉａｎＳｉｔｅ,ｆａｍｏｕｓ“ｈｏｍｅ”ｏｆＰｅｋｉｎｇＭａｎ,ｌｉｅｓａｐｐｒｏｘｉｍａｔｅｌｙ５０ｋｉｌｏｍｅｔｒｅｓｓｏｕｔｈｗｅｓｔｏｆｔｈｅＰｅ...     

Structures for the polynucleotide complexes poly(dA) · poly(dT) and poly(dT) · poly(dA) · poly(dT)

X-ray diffraction analyses of fibers of polydeoxyadenylic acid · polydeoxythymidylic acid show that this molecule exists as a 10-fold double-helix with axial rise per nucleotide $\text{h = 3.24}\text{to}\text{3.29}\text{A}\text{?}$. The structure is very similar to B-DNA ($\text{h = 3.37}\text{A}\text{?}$) in having C3-exo furanose rings and base-pairs positioned centrally on the helix axis, but distinctive enough to have two packing modes, neither of which has been observed for B-DNA. Although the triple-stranded poly(dT) · poly(dA) · poly(dT) also has a large value of h(3.26 Å), each of the chains is a 12-fold helix of the A-genus with C3-endo furanose rings and bases displaced several Angstrom units from the helix axis.     

美国癌症研究所(NCI)科研规划简介(续)

3 临床治疗 3.1 临床肿瘤学拨款临床肿瘤学规划提供的拨款,支持研究治疗人类癌症中抗癌剂的应用及其效果的评估。它包括四个特殊领域:化疗药物的毒性和效果,单独激素治疗或同其它治疗方式相结合的临床研究;用动物模型和细胞系统发展治疗研究;对可能干扰抗癌药物活性,与癌有关的失调进行研究;进行癌症临床试验新方法的研究。该规划拨款还对癌症治疗时引起癌症患者承担的潜伏生命威胁处境给予支持。出血控制时的血小板转输,白血球输送,     

Synthesis of (S)-(—)-Vertinolide

(S)-(?)-Vertinolide 1 was synthesized via the tetronic acid derivative 6 from (S)-(?)-tetrahydro-2-methyl-5-oxo-2-furancarboxylic acid 3. (±)-Vertinolide was also synthesized from (±)-3.     

Charge Transport in Poly(dG)–Poly(dC) and Poly(dA)–Poly(dT) DNA Polymers

We investigate the charge transport in synthetic DNA polymers built up from single type of base pairs. In the context of a polaronlike model, for which an electronic tight-binding system and bond vibrations of the double helix are coupled, we present estimates for the electron-vibration coupling strengths utilizing a quantum-chemical procedure. Subsequent studies concerning the mobility of polaron solutions, representing the state of a localized charge in unison with its associated helix deformation, show that the system for poly(dG)–poly(dC) and poly(dA)–poly(dT) DNA polymers, respectively possess quantitatively distinct transport properties. While the former supports unidirectionally moving electron breathers attributed to highly efficient long-range conductivity, the breather mobility in the latter case is comparatively restrained, inhibiting charge transport. Our results are in agreement with recent experimental results demonstrating that poly(dG)–poly(dC) DNA molecules acts as a semiconducting nanowire and exhibit better conductance than poly(dA)–poly(dT) ones.     

Studies on synthetic chromatins containing poly(dA-dT)·poly(dA-dT) and poly(dG-dC)·poly(dG-dC)

Core histones, (H2A,H2B,H3,H4)₂, were reconstituted with the synthethic polynucleotides poly(dA-dT)·poly(dA-dT) and poly(dG-dC)·poly(dG-dC) to yield synthetic chromatins containing 200 basepairs per octamer. These synthetic chromatins displayed a 36% decrease in the circular dichroism (CD) peak ellipticity from the value of the polynucleotide free in solution; the poly(dA-dT)·poly(dA-dT)/chromatin showed an increase in the complexity of the thermal denaturation profile compared to that of the polynucleotide. Both the temperature of maximum $\text{d}\text{h}\text{d}\text{T}$ for each transition (T_m) and the relative amount of poly(dA-dT)·poly(dA-dT) in the synthetic chromatin melting in each of the four thermal transitions is a function of the ionic strength over the 0–5 mM sodium phosphate range (0.25 mM EDTA, pH 7.0); a shift of material toward higher melting transitions was observed with increasing ionic strength. The CD peak ellipticity value for both synthetic chromatins was ionic strength-independent over the 0–5 mM sodium phosphate range. These results are in contrast to those observed with $\text{H}\text{1}\text{H}\text{5}$ stripped chicken erythrocyte chromatin (Fulmer, A. and Fasman, G.D. (1979) Biopolymers 18, 2875–2891), where an ionic strength dependence was found. Differences in the CD spectra between poly(dA-dT)·poly(dA-dT)/chromatin, poly(dG-dC)·poly(dG-dC)/chromatin and $\text{H}\text{1}\text{H}\text{5}$ stripped chicken erythrocyte chromatin suggest subtle differences in assembly. Finally, the temperature dependence of the CD spectra of poly(dA-dT)·poly(dA-dT)-containing synthetic chromatin, which is similar to that for the polynucleotide, suggests the core histone bound polynucleotide has a large degree of conformational flexibility allowing it to undergo the premelt transition.     

microRNA (miRNA) speciation in Alzheimer’s disease (AD) cerebrospinal fluid (CSF) and extracellular fluid (ECF)

Human cerebrospinal fluid (CSF), produced by the choroid plexus and secreted into the brain ventricles and subarachnoid space, plays critical roles in intra-cerebral transport and the biophysical and immune protection of the brain. CSF composition provides valuable insight into soluble pathogenic bio-markers that may be diagnostic for brain disease. In these experiments we analyzed amyloid beta (Aβ) peptide and micro RNA (miRNA) abundance in CSF and in short post-mortem interval (PMI <2.1 hr) brain tissue-derived extracellular fluid (ECF) from Alzheimer’s disease (AD) and age-matched control neocortex. There was a trend for decreased abundance of Aβ42 in the CSF and ECF in AD but it did not reach statistical significance (mean age ~72 yr; N=12; p~0.06, ANOVA). The most abundant nucleic acids in AD CSF and ECF were miRNAs, and their speciation and inducibility were studied further. Fluorescent miRNA-array-based analysis indicated significant increases in miRNA-9, miRNA-125b, miRNA-146a, miRNA-155 in AD CSF and ECF (N=12; p<0.01, ANOVA). Primary human neuronal-glial (HNG) cell co-cultures stressed with AD-derived ECF also displayed an up-regulation of these miRNAs, an effect that was quenched using the anti-NF-кB agents caffeic acid phenethyl ester (CAPE) or 1-fluoro-2-[2-(4-methoxy-phenyl)-ethenyl]-benzene (CAY10512). Increases in miRNAs were confirmed independently using a highly sensitive LED-Northern dot-blot assay. Several of these NF-кB-sensitive miRNAs are known to be up-regulated in AD brain, and associate with the progressive spreading of inflammatory neurodegeneration. The results indicate that miRNA-9, miRNA-125b, miRNA-146a and miRNA-155 are CSF- and ECF-abundant, NF-кB-sensitive pro-inflammatory miRNAs, and their enrichment in circulating CSF and ECF suggest that they may be involved in the modulation or proliferation of miRNA-triggered pathogenic signaling throughout the brain and central nervous system (CNS).     

红豆杉(Taxus chinensis (Pilger) Rehd.)化学成分研究(简报)

自七十年代发现了紫杉醇（taxol）独特的抗癌机制一促进微管蛋白聚合、抑制微管蛋白解聚后,紫杉醇及其类似物紫杉烷类二该化合物的资源调查和化学研究倍受重视。紫杉醇主要存在于红豆杉科的大多数植物中,红豆杉科（Taxaceae）红豆杉属（TaxuS）植物全球大约有11种,我国有4种和1个变种。我们从采自湖北神农架的红豆杉（Tchinens周树皮中分离得到8个结晶性物质,本文报道其中已鉴定的3个成分,即taxinineJ（l）,ldiydroxybaccatinl（2）和taxol（3）。据文献报道,已经从红豆杉分离得到二十多种紫杉烷类化合物l'l,而我们分离得到的1和2…     

Cystine-knot peptides engineered with specificities for α(IIb)β(3) or α(IIb)β(3) and α(v)β(3) integrins are potent inhibitors of platelet aggregation

A truncated form of the Agouti‐related protein (AgRP), a member of the cystine‐knot family, has shown promise as a scaffold for engineering novel peptides with new molecular recognition properties. In this study, we replaced a constrained six amino acid loop in AgRP with a nine amino acid loop containing an Arg–Gly–Asp integrin recognition motif, and randomized the neighboring residues to create a library of ～20 million AgRP variants. We displayed the AgRP mutants as fusions on the surface of yeast and used high‐throughput fluorescence‐activated cell sorting (FACS) to isolate peptides that bound specifically to the platelet integrin α_IIbβ₃, a clinically important target for the prevention and treatment of thrombosis. These AgRP peptides had equilibrium dissociation (K_D) constants for α_IIbβ₃ integrin ranging from 60 to 90 nM, and did not bind to α_vβ₃, α_vβ₅, or α₅β₁ integrins. Using an alternate library screening strategy, we identified AgRP peptides that bound to both α_IIbβ₃ and α_vβ₃ integrins with K_D values ranging from 40 to 70 nM and 20 to 30 nM, respectively, and did not bind to α_vβ₅ or α₅β₁ integrins. Unique consensus sequences were identified within both series of AgRP peptides suggesting alternative molecular recognition events that dictate different integrin binding specificities. In addition, the engineered AgRP peptides prevented platelet aggregation as well as or slightly better than the FDA‐approved cyclic peptide eptifibatide. Collectively, these data demonstrate that cystine‐knot peptides can be generated with high affinity and specificity to closely‐related integrins, and provide insights into molecular interactions between small, structured peptide ligands and their receptors. Copyright © 2010 John Wiley & Sons, Ltd.     

人类生态学(七):野生动物管理(1)

地球上的生物已有大约40亿年的进化史,而人类的起源和进化大约只经历了400万年,约占整个生物进化史的1‰。人类是地球上最晚出现的一种智慧生物,人类起源于生物界,而又离不开生物界。在人类进化历史的绝大部分时期内,人类几乎完全依赖野生生物为生(靠狩猎和采集野生植物),只是在1万多年以前,当农业和畜牧业产生以后,人类才逐渐减少了对野生生物的依赖性(目前仍有许多国