Genetic studies of the Syrian hamster. IX. Linkage between the sex-linked genes Mottled-white and Tortoiseshell

The sex-linked genes Mo and To are shown to have a crossover frequency of 10.4±4.4 per cent. It is proposed that the sex-linked genes be designated as the XXII linkage group.     

Human RNaseP RNA and nucleolar 7-2 RNA share conserved ‘To’ antigen-binding domains

RNase P in both prokaryotes and eukaryotes is a ribonucleoprotein that cleaves tRNA precursors to generate the 5 termini of the mature tRNAs. Many patients with autoimmune diseases produce antibodies against a 40 kDa protein (designatedTo orTh antigen) which is an integral component of eukaryotic RNaseP as well as nucleolar 7-2 RNP which is identical to the mitochondrial RNA processing (MRP) RNP. Interestingly, theTo antigen found in human cells and the C5 protein, the only protein component ofE. coli RNaseP, are antigenically related. In this study, we show that a 56 nucleotide-long sequence, corresponding to nucleotides 20–75 near the 5 end of human RNaseP RNA, is sufficient to bind theTo antigen. We previously showed that the humanTo antigen binds to a short distinct structural domain near the 5 end of human 7-2/MRP RNA. There is no obvious primary sequence homology between theTo antigen binding sites in RNaseP RNA and 7-2/MRP RNA; however, these sequences are capable of assuming a similar secondary structure which corresponds to the recently proposed cage structure for RNaseP RNAs and 7-2/MRP RNA (Forster and Altman (1989) Cell 62: 407–409). These data are supportive of the idea that these two RNAs may have evolved from a common progenitor molecule.     

Accelerated evolution of Trimeresurus okinavensis venom gland phospholipase A2 isozyme-encoding genes

Three Trimeresurus okinavensis (To; himehabu snake, Crotalinae) venom gland phospholipase A₂ (PLA₂) isozymeencoding genes, gPLA₂-o1, gPLA₂-o2 and gPLA₂-o3, were isolated from its genomic DNA library. The nucleotide (nt) sequence analysis revealed that two of the three genes (gPLA₂-o2) and (gPLA₂-o3) occasionally have been converted to inactivated genes by introduction of one base insertion or substitution. It was confirmed from Southern blot analysis that the To haploid genome contains only three venom gland PLA₂ isozyme genes herein isolated. Comparison of these genes showed that nonsynonymous nt substitutions have occurred more frequently than synonymous nt substitutions in the protein-coding regions, except for the signal-peptide coding domain, implying that To venom gland PLA₂isozyme genes have evolved via accelerated evolution. Such an evolutionary feature of To venom gland PLA₂ isozyme genes proves the general universality of accelerated evolution previously drawn for venom gland PLA₂ isozyme genes of other crotalinae snakes. The variability in the mature protein-coding regions of three To venom gland PLA₂ isozyme genes appears to have been brought about by natural selection for point mutations.     

关于终末期糖尿病肾病的医疗保险研究

目的 探索终末期肾病的保险精算方法,为终末期肾病以及其他重大疾病的保险研究方法提供参考和借鉴。为完善我国终末期肾病的医疗保障提供理论依据。方法 拟和糖尿病病人终末期肾病发病概率模型、生存概率模型,采用寿险精算的思想 , 考虑长期保险过程中利率因素的影响,建立终末期糖尿病肾病的保险方案。结果 糖尿病患者终末期肾病的发病率随年龄增加而上升。保费与投保时年龄有关。对于终身长期疾病保险,利率的变化对保费的影响较大。结论 将寿险精算的方法应用到糖尿病终末期肾病保险中具有可行性,随着糖尿病的发病率迅速上升,终末期肾病造成的经济负担需要健全和完善的社会医疗保障体系。     

Characterization of pyranose oxidase variants for bioelectrocatalytic applications

Pyranose oxidase (POx) catalyzes the oxidation of d-glucose to 2-ketoglucose with concurrent reduction of oxygen to H₂O₂. POx from Trametes ochracea (ToPOx) is known to react with alternative electron acceptors including 1,4-benzoquinone (1,4-BQ), 2,6-dichlorophenol indophenol (DCPIP), and the ferrocenium ion. In this study, enzyme variants with improved electron acceptor turnover and reduced oxygen turnover were characterized as potential anode biocatalysts. Pre-steady-state kinetics of the oxidative half-reaction of ToPOx variants T166R, Q448H, L545C, and L547R with these alternative electron acceptors were evaluated using stopped-flow spectrophotometry. Higher kinetic constants were observed as compared to the wild-type ToPOx for some of the variants. Subsequently, the variants were immobilized on glassy carbon electrodes. Cyclic voltammetry measurements were performed to measure the electrochemical responses of these variants with glucose as substrate in the presence of 1,4-BQ, DCPIP, or ferrocene methanol as redox mediators. High catalytic efficiencies (I_max^app/K_M^app) compared to the wild-type POx proved the potential of these variants for future bioelectrocatalytic applications, in biosensors or biofuel cells. Among the variants, L545C showed the most desirable properties as determined kinetically and electrochemically.     

ELECTROPHORETIC AND MORPHOMETRIC CHARACTERS IN POPULATION DIFERENTIATION OF THE PEARL OYSTER, PINCTADA RADIATA (LEACH), FROM AROUND BAHRAIN

Variation at the leucine aminopeptidase (Lap), glucose phosphateisomerase (Gpi) and tetrazolium oxidase (To) loci was investigatedin samples of three populations, Al-Mayana (MAY), Shigita (SH)and Mina Salman (MS), of Pinctada radiata from pearl oysterbeds around Bahrain. The To locus was monomor-phic. SignificantLap and Gpi heterozygote deficiencies were evident and it issuggested that these were generated by selection. The MS population,to the East of Bahrain, differed significantly in Gpi allelefrequencies from both Northern populations (MAY, SH) and Nei'sgenetic identity indicates a close relationship between theNorthern populations. Measurements of shell morphometrics were used both as ratiosof one dimension to another, and as regressions of one dimensionon another to examine relatedness between populations. Boththese mor-phometric approaches gave different results from eachother and also differed from the electrophoretic data. It isconcluded that estimates of relatedness in pearl oysters basedon electrophoretic data will be more reliable than those basedon shell shape. (Received 20 November 1990; accepted 12 April 1991)     

Selection of resistance breaking strains of tomato spotted wilt tospovirus

In glasshouse tests, sap from plants infected with 15 different isolates of tomato spotted wilt tospovirus (TSWV) from three Australian states was inoculated to nine genotypes of tomato carrying TSWV resistance gene Sw-5 or one of its alleles. A further two resistant tomato genotypes were inoculated with four isolates each. The normal response in resistant genotypes was development of necrotic local lesions in inoculated leaves without systemic invasion, but 22/752 plants also developed systemic reactions in addition to local hypersensitive ones. Using cultures from two of these systemically infected plants and following four cycles of subculture in TSWV resistant tomato plants, two isolates were obtained that gave susceptible type systemic reactions but no necrotic spots in inoculated leaves of resistant tomatoes. When these two isolates, Da_WA-1d and To_TAS-1d, were maintained by repeated subculture for 10 successive cycles in Nicotiana glutinosa or a susceptible tomato genotype, they still induced susceptible type systemic reactions when inoculated to resistant tomato plants. They were therefore stable resistance breaking isolates as regards overcoming gene Sw-5. When resistance-breaking isolate Da_WA^-1ld multiplied together with original isolate Da_WA-l in susceptible tomato, it was fully competitive with the original isolate. However, when Da_WA-ld and To_TAS-ld were inoculated to TSWV resistant Lycopersicon peruvianum lines PI 128660R and PI 128660S and to TSWV resistant Capsicum chinense lines PI 152225, PI 159236 and AVRDC CO0943, they failed to overcome the resistance, producing only necrotic local lesions without systemic infection. Thus, although the ease of selection, stability and competitive ability of resistance breaking isolates of TSWV is cause for concern, L. peruvianum and C. chinense lines are available which are effective against them. The effectiveness of the resistance to TSWV in nine tomato genotypes was examined in a field experiment. Spread was substantial in the susceptible control genotype infecting 42% of plants. Resistance was ineffective in cv. Bronze Rebel, 26% of plants developing infection. In contrast, it held up well in the other eight resistant genotypes with only 1–3 or no plants of each becoming infected. Accumulated numbers of Thrips tabaci, Frankliniella occidentalis and F. schultzei were closely correlated with TSWV spread.     

Amylose Content,Morphology, Crystal Structure,and Thermal Properties of Starch Grains in Main and Ratoon Rice Crops

Rice ratooning, or the production of a second rice crop from stubble after the harvest of the main crop, is considered to be a green and resource-efficient rice production system. The present study was conducted to examine variance in amylose content (AC), grain morphology, crystal structure, and thermal properties of starch between main- and ratoon-season rice of seven varieties. Ratoon-season rice grains had higher ACs and significantly lower transition gelatinization temperatures (To, Tp, and Tc) than did main-season rice grains. The relative crystallinity and lamellar peak intensity of ratoon-season rice starch were 7.89% and 20.38% lower, respectively, than those of main-season rice starch. In addition, smaller granules with smoother surfaces and lower thermal parameters were observed in the starch of ratoon-season rice. The relative crystallinity and lamellar peak intensity of starch correlated negatively with the AC and positively with transition gelatinization temperatures. These results suggest that the superior cooking quality of ratoon-season rice is attributable to the moderate increase of grain AC, which reduces the relative crystallinity, weakens the crystal structure, and lead to a decrease in the gelatinization temperature.     

基于结构变动度的不同付费方式住院医疗费用控制研究

目的 探讨住院医疗费用的结构构成,分析不同付费方式下影响费用结构变动的趋势与特征,为控制住院医疗费用不合理增长提供循证依据。方法 采用结构变动度、结构变动值和结构变动贡献率等指标进行统计分析。结果 住院医疗费用结构变动度达7.84%,以2012—2013年变动振幅较大;药品费、治疗费、化验费是引起结构变动的主要项目,三者累计贡献率为78.38%;其中化验费和治疗费呈持续正向变动,药品费呈持续负向变动。结论 控制住院医疗费用应结合不同付费方式分类制宜,药品费和检查化验费比重过高,而体现医护人员医疗服务价值的诊疗手术费等过低,费用结构有待优化,医疗服务价格与支付制度改革势在必行。     

A specific amino acid residue in the catalytic site of dandelion polyphenol oxidases acts as ‘selector’ for substrate specificity

Key message

Successful site-directed mutagenesis combined with in silico modeling and docking studies for the first time offers experimental proof of the role of the ‘substrate selector’ residue in plant polyphenol oxidases.

Abstract

The plant and fungi enzymes responsible for tissue browning are called polyphenol oxidases (PPOs). In plants, PPOs often occur as families of isoenzymes which are differentially expressed, but little is known about their physiological roles or natural substrates. In a recent study that explored these structure–function relationships, the eleven known dandelion (Taraxacum officinale) PPOs were shown to separate into two different phylogenetic groups differing in catalytic cavity architecture, kinetic parameters, and substrate range. The same study proposed that the PPOs’ substrate specificity is controlled by one specific amino acid residue positioned at the entrance to the catalytic site: whereas group 1 dandelion PPOs possess a hydrophobic isoleucine (I) at position H_B2+1, group 2 PPOs exhibit a larger, positively charged arginine (R). However, this suggestion was only based on bioinformatic analyses, not experiments. To experimentally investigate this hypothesis, we converted group 1 ToPPO-2 and group 2 ToPPO-6 into PPO-2-I₂₄₄R and PPO-6-R₂₅₄I, respectively, and expressed them in E. coli. By performing detailed kinetic characterization and in silico docking studies, we found that replacing this single amino acid significantly changed the PPO’s substrate specificity. Our findings therefore proof the role of the ‘substrate selector’ in plant PPOs.

     

日化产品中洋葱伯克霍尔德氏菌复合群(Bcc)的分类和神秘伯克霍尔德氏菌的耐药性研究

【目的】对从2020–2022年不同日化产品中分离的29株洋葱伯克霍尔德氏菌复合群(Burkholderia cepacia complex,Bcc)进行分类和分型,另将2020年前来源于日化产品中6株被鉴定为Burkholderia lata的菌株进行分类更正。探究神秘伯克霍尔德氏菌(Burkholderia aenigmatica)的耐药性。【方法】本文主要应用多位点分型研究方法(multilocus sequence typing,MLST),PCR扩增atpD、gltB、gyrB、recA、lepA、phaC和trp B 7个管家基因片段,将测序结果与MLST数据库中的数据比对分析,获得菌株各管家基因的编号和ST型(sequence type),对本检测中心分离自日化产品的Bcc进行分型;利用多位点序列分析(multilocus sequence analysis,MLSA),结合MLST中等位基因的核苷酸序列构建进化树,从而对Bcc进行系统发育分析和鉴定。利用最小抑菌浓度法(minimum inhibitory concentration,MIC)测定Bcc对常见防腐剂(1,...     

Structure, bonding, and ligand-based reactions of zwitterionic boratoiridium(I) complexes with oxazolinyl scorpionate ligands

New tris(4,4-dimethyl-2-oxazolinyl)phenylboratoiridium(I) scorpionate-type compounds [Ir(To^M)L₂] (L₂ = η⁴-C₈H₁₂ and (CO)₂) and electrophiles form adducts that contain a bidentate IrTo^M-coordination and an N-electrophile interaction of the third oxazoline instead of the oxidative addition product. The adduct with lithium chloride gives a unique heterobimetallic Li-O-oxazoline-N-Ir bridging structure that has been identified through X-ray crystallography. Density functional theory calculations provide thermodynamic data, orbital symmetries, and orbital energies that explain the formation of the observed iridium(I) products.     

乌头产吲哚乙酸内生细菌遗传多样性、抗逆性及其对水稻幼苗生长的影响

[目的]探究乌头产吲咮乙酸(IAA)内生细菌的遗传多样性、溶磷解钾能力、抗逆能力及其对水稻幼苗生长的影响,为道地产区乌头产业可持续发展提供科技支撑.[方法]从健康乌头植株分离可培养内生细菌,采用Salkowski比色法测定内生细菌产IAA能力,16S rDNA限制性片段长度多样性(16S rDNA-RFLP)及16S ...     

我国护理人员绩效考核的发展研究

目的 了解我国护理人员绩效考核的现状及其发展趋势,分析目前我国护理人员绩效考核体系的结构,为建立完善、有效的护理人员考核体系提供思路。 方法 检索中文数据库中核心期刊上公开发表的关于护理人员绩效考核的论文,对其进行描述性和半定量分析。 结果 我国护理人员的绩效考核经历了从经验性介绍到应用性研究的过程,研究方法逐渐由描述性向方法学研究发展。结论 目前国内关于护理人员考核体系的种类较多,缺乏统一的标准,考核结果在全国范围内缺乏可比性。

     

Noradrenergic and adrenergic systems in the brain of the urodele amphibian,Pleurodeles waltlii,as revealed by immunohistochemical methods

The distribution of noradrenaline and adrenaline in the brain of the urodele amphibian Pleurodeles waltlii has been studied with antibodies raised against noradrenaline and the enzymes dopamine--hydroxylase and phenylethanolamine-N-methyltransferase. Noradrenaline-containing cell bodies were found in the anterior preoptic area, the hypothalamic nucleus of the periventricular organ, the locus coeruleus and in the solitary tract/area postrema complex at the level of the obex. Noradrenergic fibers are widely distributed throughout the brain innervating particularly the ventrolateral forebrain, the medial amygdala, the lateral part of the posterior tubercle, the parabrachial region and the ventrolateral rhombencephalic tegmentum. Putative adrenergic cell bodies were found immediately rostral to the obex, ventral to the solitary tract. Whereas the cell bodies and their dendrites were Golgi-like stained, axons were more difficult to trace. Nevertheless, some weakly immunoreactive fibers could be traced to the basal forebrain. A comparison of these results with data previously obtained in anurans reveals not only several general features, but also some remarkable species differences.Abbreviations Acc Nucleus accumbens - AP area postrema - Apl amygdala, pars lateralis - Apm amygdala, pars medialis - ca commissura anterior - Cb cerebellum - cc central canal - Dp dorsal pallium - epl external plexiform layer - gl glomerular layer of the olfactory bulb - H ganglion habenulae - igl internal granular layer - Ip nucleus interpeduncularis - Lc locus coeruleus - Ll lateral line lobe - Lp lateral pallium - Ls lateral septum - ml mitral cell layer - Mp medial pallium - Ms medial septum - nPT nucleus pretectalis - NPv nucleus of the periventricular organ - nV nervus trigeminus - oc optic chiasm - Poa preoptic area - Ri nucleus reticularis inferior - SC nucleus suprachiasmaticus - sol solitary tract - Str striatum - thd thalamus dorsalis - thv thalamus ventralis - To tectum opticum - TP tuberculum posterius - V ventricle - VH ventral hypothalamic nucleus - III nucleus nervi oculomotorii - IXm nucleus motorius nervi glossopharyngei - Xm nucleus motorius nervi vagi     

Respiratory-cardiovascular physiology and chloroethane gill flux in the channel catfish, Ictalurus punctatus

A fish respirometer-metabolism chamber was used to obtain in vivo respiratory-cardiovascular and chloroethane gill flux data on transected channel catfish (Ictalurus punctatus). Methods used for spinal transection, attachment of an oral membrane (respiratory mast), placement and attachment of blood cannulas and urine catheters are described. Respiratory physiology, cardiac output and chemical extraction efficiencies for 1,1,2,2-tetrachloroethane (TCE), pentachloroethane (PCE), and hexachloroethane (HCE) were determined on 419–990 g catfish. The overall mean values (± s.d.) for ventilation volume (Q_v), effective respiratory volume (Q_w), oxygen consumption (Vo₂ and percentage utilization of oxygen (U) were 17-3 ±4–71 h^?1 kg^?1, 9·8±l·71 h^?1 kg^?1, 71·6±12·5mg h^?1 kg^?1, and 49± 10%, respectively, while cardiac output calculated via the Fick Method was 2·4±0·61 h^?1 kg^?1. Additional measurements were made on ventilation rate (V_r), total plasma protein, haematocrit (Hct), and urine volume; while both arterial and venous blood were analysed for pH, oxygen partial pressure (P02), carbon dioxide partial pressure (Pco₂), total oxygen (To₂), total carbon dioxide (Tco₂) and total ammonia (TAMM). Physiological measurements taken at 24 h were not significantly different from those taken at 48 h and indicated no deterioration of the in vivo preparation. All of these values agreed well with literature values on UTitransected channel catfish, except for Hct which was lower for cannulated animals used in this study. Overall, these data provide strong support for the use of transected channel catfish for in vivo collection of physiological and chemical gill flux data. The mean initial chemical extraction efficiencies for TCE, PCE and HCE were 41, 61 and 73%, respectively. Chemical clearances (Cl_X) for these same three chemicals were 5·9, 9·3 and 10·8 1 h^?1 kg^?1, respectively. The approximate 1: 1 relationship between effective respiratory volume (Q_w) and chemical clearance (Cl_x) indicated that branchial uptake of PCE and HCE was water flow-limited. Chemical gill flux observed for channel catfish and chloroethanes was similar to that observed for rainbow trout in previous studies and provided further support for the flow-limited model of chemical flux across fish gills.     

Helix-coiled transition in heteropolymers. I. Ground-state energy

A new technique is presented for treating the ground state of an heteropolymer with a random sequence of components. An exact system of equations is found for determining the ground state energy E which is equal to the polymer free energy f in the lowest-order approximation in T/V (V/2 is the large “surface” energy arising at the boundaries between coiled and “helical” sections: V ? T, U_k; U₁ and –U₂ are the free energies of the components counted from the corresponding coiled state energies). These equations are essentially simplified at certain fixed values of the ratio U₁/U₂. For integer values of U₂/U₁ and U₁/U₂ a solution is obtained with an accuracy exp(–V/U_k). The ground-state energy as a function of U₁ and U₂ is shown to be highly irregular: its derivatives have jumps at an infinite number of points. These jumps provide a fine structure of the melting curves. A smoothed over the jumps function E′ is found by way of analytic continuation from the integer values of U₁/U₂ and U₂/U₁. The accuracy of the approximation f ≈ E is estimated and the correctional term of order T/V is determined.