Effect of bis(acetato)tetrakis(imidazole) copper(II) in delaying the onset and reducing the mortality rate of strychnine- and thiosemicarbazide—Induced convulsions

The anticonvulsant activity of bis(acetato)tetrakis(imidazole) copper(II), Cu(OAc)₂(Im)₄, was studied in normal mice using chemical convulsions induced by strychnine, thiosemicarbazide, picrotoxin, and pentelenetetrazol. Intraperitoneal administration of Cu(OAc) ₂(Im)₄, 50 mg/kg body mass, has delayed the onset of strychnine (3 mg/kg)-induced convulsion by 204% (p≤0.005) and thiosemicarbazide (20 mg/kg)-induced convulsant by 61% (p≤0.005). The changes in the onset of picrotoxin-(6 mg/kg) and pentelenetetrazol (50 mg/kg)-induced convulsions were not significant. The same dosage of the copper compound was effective in delaying the lethal time and reducing the mortality rate of treated animals. The anticonvulsant activity of Cu(OAc) ₂(Im)₄ complex against strychnine was not related to its constituents because the inorganic form of copper such as copper chloride, copper acetate, and the parent imidazole has no anticonvulsant activity. Other copper(II) complexes like copper(II)aspirinate and bis(acetato)bis(2-methyl imidazole) copper(II) were less effective.     

The structure and properties of tetrakis(tironato)cerate(IV), Na12[Ce(C6H2O2(SO3)2)4]·9H2O·6C3H7NO

The title complex, prepared in 1 M NaOH, was crystallized from hot N,N-dimethylformamide/ ethanol solutions to give Na₁₂[Ce(C₆H₂O₂(SO₃)₂)₄]· 9H₂O·6DMF. The purple—brown crystals were examined by X-ray diffraction while inside quartz capillaries filled with DMF, (λ_max 425 nm, ϵ 3664; λ_sh 520 nm, ϵ 2240) and belong to space group Pbca, Z=8 with a=21.846(4), b=17.348(2), c=43.103- (6) Å, V=16.335(7) ų, D_c=1.693 gcm^t−3, D_o=1.725 g cm^t−3. Diffractometer data were collected using Mo Kα radiation to 2θ=43^o. For 7331 independent data with F_o²>3σ(F_o²) full matrix least squares refinement converged to unweighted and weighted R factors of 0.072 and 0.110, respectively, with a mixture of anisotropic and isotropic thermal parameters. The disordered DMF atom parameters were not refined. The structure consists of discrete monomeric Ce(C₆H₂S₂O₈)₄¹²⁻ units with 12 Na⁺ counter cations and 10 H₂O molecules (two with half occupancy), and 6 DMF molecules of solvation filling up spaces between cations and anions. Cerium(IV) is in a general position with a coordination polyhedron close to the trigonal-faced dodecahedron, D_2d, with the angles between the two BAAB trapezoids of 2.3^o and 3.7^o. The average CeO(A) distance, 2.363(9) Å is longer than the average CeO(B) distance, 2.326(15)Å, with the reverse being true for one of the four tironato ligands. The average ring OCeO angle is 67.9(1)^o. The cerium (IV) complex is found by cyclic voltammetry to undergo a quasi-reversible one-electron reduction (in strongly basic solution with excess tiron) with Ef=−497 mV vs. SCE, hence the ratio of the formation constants for tetrakis(tironato)cerate(IV) to that for tetrakis(tironato)cerate(III), K_IV/K_III, is 10³³. Characterization of other tiron salts is reported.     

Preparation,spectroscopy and crystal structure of a novel tetranuclear copper(I) benzimidazoline-2-thione complex: cyclo-hexakis-μ2-(benzimidazoline-2-thione) tetrakis[benzimidazoline-2-thione copper(I)] perchlorate quatrodeca hydrate

Reaction between copper(II) perchlorate and benzimidazole-2-thione (bzimztH) in aqueous ethanol produced a pale green crystalline solid of empirical formula [Cu₂(bzimztH)₅](ClO₄)₂·7H₂O. The compound is diamagnetic at room temperature and possesses no d-d absorption in its electronic spectrum.The crystal structure of the compound contains centrosymmetrically constrained tetranuclear cations [Cu₄(bzimztH)₁₀]⁴⁺, perchlorate anions and water molecules in a monoclinic unit cell [a = 14.960(2), b = 25.863(3), c = 14.031(2) Å, β = 110.331(8)°, space group P2₁/c, Z = 2]. The tetranuclear cations contain a planar centrosymmetric array of copper(I) atoms, Cu₄, with edge dimensions of 2.681(2) and 4.216(3) Å and an internal angle of 85.8(1)°.Each copper(I) atom is tetrahedrally coordinated by four S-donating ligands. The ten ligands in the cation consists of four terminal S-donating, one asymmetric μ₂-S bridging ligand along each of the long edges of the Cu₄ array and four asymmetric μ₂-S bridging ligands arranged in pairs along each of the short edges of the Cu₄ array. The latter generate pairs of Cu₂S₂ units narrow angles at the bridging S atoms, 69.1(1)° and 66.8(1)°. The remaining bridging angle is much larger, 124.9(1)°. CuS distances are in the range 2.262(2) to 2.499(3) Å with the terminal distances somewhat shorter than the bridging ones. An alternating sequence of long and short CuS distances, created by the μ₂-S bzimztH ligands, links the copper atoms of the Cu₄ array. The final R index for 4672 observed reflections is 0.092.     

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).     

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