On the species status of the root-knot nematode Meloidogyne ulmi Palmisano & Ambrogioni, 2000 (Nematoda,Meloidogynidae)

The root-knot nematode Meloidogyne ulmi is synonymised with Meloidogyne mali based on morphological and morphometric similarities, common hosts, as well as biochemical similarities at both protein and DNA levels. M. mali was first described in Japan on Malus prunifolia Borkh.; and M. ulmi in Italy on Ulmus chenmoui W.C. Cheng. Morphological and morphometric studies of their holo- and paratypes revealed important similarities in the major characters as well as some general variability in a few others. Host test also showed that besides the two species being able to parasitize the type hosts of the other, they share some other common hosts. Our study of the esterase and malate dehydrogenase isozyme phenotypes of some M. ulmi populations gave a perfectly comparable result to that already known for M. mali. Finally, phylogenetic studies of their SSU and LSU rDNA sequence data revealed that the two are not distinguishable at DNA level. All these put together, leave strong evidences to support the fact that M. ulmi is not a valid species, but a junior synonym of M. mali. Brief discussion on the biology and life cycle of M. mali is given. An overview of all known hosts and the possible distribution of M. mali in Europe are also presented.     

Climate fluctuation effects on breeding of blue penguins (Eudyptula minor)

Abstract

El Niño and La Niña climate perturbations alter sea currents and food availability for seabirds in many areas of the world. This changes their breeding success and mortality. Blue penguin (Eudyptula minor) breeding success is dependent upon whether one or two clutches per season are laid, and the hatching and fledging success of these clutches. This study uses six years of data from five blue penguin breeding colonies, three from Taiaroa Head, Otago Peninsula and two from Oamaru, to examine whether annual variation in breeding success correlates with El Niño/La Niña perturbations. When La Niña conditions prevailed, penguins started breeding later, and there was a lower proportion of double breeders than in El Niño and normal years. The probability of a newly hatched chick surviving to fledging was also dependent on whether large‐scale climatic conditions prevailed, whereas hatching success and overall breeding success (number of fledged chicks per breeding pair) showed no correlation with climate perturbations.     

Transitional Paternalism: How Shared Normative Powers Give Rise to the Asymmetry of Adolescent Consent and Refusal

In many jurisdictions, adolescents acquire the right to consent to treatment; but in some cases their refusals – e.g. of life‐saving treatment – may not be respected. This asymmetry of adolescent consent and refusal seems puzzling, even incoherent. The aim here is to offer an original explanation, and a justification, of this asymmetry. Rather than trying to explain the asymmetry in terms of a variable standard of competence – where the adolescent is competent to consent to, but not refuse, certain interventions – the account offered here focuses more closely on the normative power to render actions permissible. Where normative powers are shared they can readily give rise to an asymmetry between consent and refusal. We then turn to why it is justifiable that normative powers be shared in adolescence. Transitional paternalism holds that the acquisition of normative powers by competent adolescents should not be an instant one, achieved in a single step, but that there should be a transitional period where paternalistic protection is rolled back, but not entirely withdrawn until a later date. Transitional paternalism could be implemented without generating the asymmetry between consent and refusal but, it is argued, the asymmetric version of transitional paternalism is to be preferred insofar as it offers a greater respect for the adolescent's decisions than the symmetrical alternative.     

Genetic variations in VDR associated with prostate cancer risk and progression in a Korean population

Low levels of vitamin D are implicated as a potential risk factor for prostate cancer, and the vitamin D receptor (VDR) gene may be important in the onset and progression of prostate cancer. In this study, sequence variants in the VDR gene were investigated in a Korean study cohort to determine whether they are associated with prostate cancer risk. We evaluated the association between 47 single nucleotide polymorphisms (SNPs) in the VDR gene and prostate cancer risk as well as clinical characteristics (prostate-specific antigen level, clinical stage, pathological stage and Gleason score) in Korean men (272 prostate cancer patients and 173 benign prostatic hyperplasia patient who underwent a prostate biopsy, which was negative for malignancy) using unconditional logistic regression. The statistical analysis suggested that two VDR sequence variants (rs2408876 and rs2239182) had a significant association with prostate cancer risk (odds ratio [OR]. 1.41; p = 0.03; OR, 0.73; p = 0.05, respectively). Logistic analyses of the VDR polymorphisms with several prostate cancer related factors showed that several SNPs were significant; nine SNPs to PSA level, three to clinical stage, two to pathological stage, and three SNPs to the Gleason score. The results suggest that some VDR gene polymorphisms in Korean men might not only be associated with prostate cancer risk but also significantly related to prostate cancer-related risk factors such as PSA level, tumor stage, and Gleason score. However, current limitation for small cohort with not-healthy control group might have false positive effects; therefore it should be overcome via further large-scale validating studies.     

Structural and Functional Studies of the Pseudomonas aeruginosa Minor Pilin,PilE

Many bacterial pathogens, including Pseudomonas aeruginosa, use type IVa pili (T4aP) for attachment and twitching motility. T4aP are composed primarily of major pilin subunits, which are repeatedly assembled and disassembled to mediate function. A group of pilin-like proteins, the minor pilins FimU and PilVWXE, prime pilus assembly and are incorporated into the pilus. We showed previously that minor pilin PilE depends on the putative priming subcomplex PilVWX and the non-pilin protein PilY1 for incorporation into pili, and that with FimU, PilE may couple the priming subcomplex to the major pilin PilA, allowing for efficient pilus assembly. Here we provide further support for this model, showing interaction of PilE with other minor pilins and the major pilin. A 1.25 Å crystal structure of PilE_Δ1–28 shows a typical type IV pilin fold, demonstrating how it may be incorporated into the pilus. Despite limited sequence identity, PilE is structurally similar to Neisseria meningitidis minor pilins PilX_Nm and PilV_Nm, recently suggested via characterization of mCherry fusions to modulate pilus assembly from within the periplasm. A P. aeruginosa PilE-mCherry fusion failed to complement twitching motility or piliation of a pilE mutant. However, in a retraction-deficient strain where surface piliation depends solely on PilE, the fusion construct restored some surface piliation. PilE-mCherry was present in sheared surface fractions, suggesting that it was incorporated into pili. Together, these data provide evidence that PilE, the sole P. aeruginosa equivalent of PilX_Nm and PilV_Nm, likely connects a priming subcomplex to the major pilin, promoting efficient assembly of T4aP.     

Enantiomeric composition of nornicotine,anatabine, and anabasine in tobacco

Literature reports on the optical purity of the minor alkaloids in tobacco leaf and its products often contradict one another. The enantiomeric compositions of nornicotine, anatabine, and anabasine were measured using gas chromatography/mass spectrometry (GC/MS) (with a chiral stationary phase) in three types of tobacco leaf (Burley, Turkish, and Virginia); three types of smokeless tobacco (loose‐leaf, dry snuff, and moist snuff); and four types of cigarettes. Regardless of the tobacco type or product, anabasine always had the highest relative percentage of the minor (R)‐(+)‐enantiomeric component (between 40 and 46% vs. 54–60% of the (S)‐(−)‐enantiomer). Of the four common tobacco alkaloids, nicotine seems to have the highest enantiomeric excess (e.e.) while anabasine has the lowest (in the tobacco leaf and tobacco products analyzed). Nornicotine and anatabine have intermediate e.e. values. Chirality 11:82–84, 1999. © 1999 Wiley‐Liss, Inc.     

DNA binding properties of minor groove binders and their influence on the topoisomerase II cleavage reaction

We present titrations of the human δβ-globin gene region with DNA minor groove binders netropsin, bisnetropsin, distamycin, chromomycin and four bis-quaternary ammonium compounds in the presence of calf thymus topoisomerase II and DNase I. With increasing ligand concentration, stimulation and inhibition of enzyme activity were detected and quantitatively evaluated. Additionally we show a second type of stimulation, the appearance of strong new topoisomerase II cleavage sites at high ligand concentrations. The specific binding sites of the minor groove binders of the DNA sequence and their microscopic binding constants were determined from DNase I footprints. A binding mechanism for minor groove binders is proposed in order to explain these results especially when ligand concentration is increased. © 1998 John Wiley & Sons, Ltd.     

桑椹粗提取物中的有效活性物质分析

桑椹中有多种有效活性物质,如多糖、氨基酸、维生素、矿物质元素、白藜芦醇、黄酮类等,在生物体内起着重要的作用,尤其是在医药领域和保健食品领域的应用更为明显,对肿瘤、病毒、心血管等方面有独特的生物活性,且细胞毒性很低。本实验提取并测定了桑椹中的多糖、氨基酸和矿物质元素等。实验测得桑椹中含有10.99%的多糖、14种氨基酸和钙、铁、钾、镁、锌以及VB1、VB2、VB3、VC等。     

Enhanced uranyl photocleavage across the minor groove of all (A/T)4 sequences indicates a similar narrow minor groove conformation

The uranyl(VI)-mediated photocleavage of a Drew–Dickerson sequence oligonucleotide (5′-dGATCACGCGAATTCGCGT) either as the (self-complementary) duplex or cloned into the BamH1 site of pUC19 has been studied. At pH 6.5 in acetate buffer relatively enhanced photocleavage is observed at the 3′-end of the AATT sequence corresponding to maximum cleavage across the minor groove in the A/T tract. Thus maximum cleavage correlates with minimum minor groove width in the crystal structure and also with the largest electronegative potential according to computations. Using plasmid constructs with cloned inserts of the type [CGCG(A/T₄)]_n, we also analysed all possible sequence combinations of the (A/T)₄ tract and in all cases we observed maximum uranyl-mediated photocleavage across the minor groove in the (A/T)₄ tract without any significant differences between the various sequences. From these results we infer that DNA double helices of all (A/T)₄ sequences share the same narrow minor groove helix conformation.     

Studies on Two Palaeozoic Seeds from China

This paper reports two species of the seed order Cardiocarpales: Cardiocarpus (?) minor (Wang) emend and Diplotesta sp. which were found in coal balls. The specimens were collected from Taiyan Formation of Upper Carboniferous near Xiedao Village, West Mountain, 'Taiyan City, Shanxi Province and Wangjiazhai Formation of Upper Permian of Wangjiazhai Mine of Shuicheng district, Guizhou Province, China. The two taxa are described and their taxonomy is discussed in detail. The diagnosis of the species (Cardiocarpus (?) minor (Wang) emend) is amended as follows: Seeds bilaterally symmetric and thinner cardioformed, appoximatly 4–6 mm long, 3–4 mm wide in the primary section and less than 2 mm thick in the secondary section. Integument differentiated into three zones. Outer sarcotesta delimkted into four layers: 1) carbonized cuticle partly preserved; 2) epidermis of thin-walled parenchyma 1–2 rows of small cells; 3) hypodermis of secretory tissue containing large cells, uniform in thickness; and 4) parenchyma layer consisting of thin-walled cells in size varying from 20 to 50 μm middle sclerotesta of vertically arranged fibers is bipartite: outer fibers being smaller in diameter and possessing thicker walls than inner fibers. Sclerotesta 80 μm in thickness commissural laterally to form two lateral ribs. Inner endotesta single rowed of parenchymatous cells. Nucellus free except at base which is attached to the integument by narrow nucellar platform. Pollen chamber not observed. The double vascular system includes integumentary strand beneath secretory layer of sarcotesta and nucellar strand which forms a tracheid mentle; the origin of integumentry and nucellar strands unknown. In addition a computerized three-dimensional reconstuction techniqne is utilized to reconstruct membrane like structure of Diplotesta sp. It is suggested that Cardiocarpus (?) minor is different from other species of the genus Cardiocarpus in the distribution of nucellar vascular tissues. This feature is thonght to be one of the important characters of bilaterally symmetrical seeds in a taxonomic view point. Therefore Cardiocarpus minor wang probally represents a menber of another new seed genus, althongh this species remains in the genus Cardiocarpus.