Cranial morphology of the Stellate Sturgeon,Acipenser stellatus Pallas 1771 (Acipenseriformes,Acipenseridae), with notes on the skulls of other sturgeons

Extant members of Acipenseridae are generally classified in four genera: Scaphirhynchus, Pseudoscaphirhynchus, Huso and “Acipenser,” which is widely recognized to be paraphyletic. Advances have been made in understanding the systematic relationships among sturgeons based on both morphological and molecular data. Analysis of mitochondrial DNA data suggested that Pseudoscaphirhynchus should be regarded as nested within “Acipenser,” specifically as sister group to the Stellate Sturgeon, A. stellatus. Recent morphological analyses also recovered this relationship, supported by a number of osteological synapomorphies, although these results were based on few and relatively small individuals. Here we describe the anatomy of the skull of A. stellatus based on newly prepared specimens of adult individuals, as well as examination of a large number of preserved individuals representing a broad range of ontogenetic stages. We present new anatomical data from all regions of the skull (dermatocranium, neurocranium, viscerocranium) and offer interpretations of these and other characters. In particular, we describe the allometry in the snout of A. stellatus, which undergoes substantial elongation relative to other sturgeons. Aspects of the skull of A. stellatus are compared to other members of the family, specifically the course of the occipital sensory canal and the morphology and distribution of cranial spines.     

Improvement of the contrast in cancer detection by autofluorescence bronchoscopy using a narrowband spectral violet excitation: A preliminary study

Autofluorescence (AF) bronchoscopy is a useful tool for early cancer detection. However, the mechanisms involved in this diagnosis procedure are poorly understood. We present a clinical autofluorescence imaging study to assess the depth of the principal contrast mechanisms within the bronchial tissue comparing a narrowband (superficial) and broadband (penetrating) violet excitation. Knowledge of this parameter is crucial for the optimization of the spectral and optical design of clinical diagnostic AF imaging devices. An intensity contrast improvement was observed with the narrowband excitation, suggesting that the heme absorption plays a key role in the AF contrast mechanism.     

Antibacterial,antifungal and in vitro antileukaemia activity of metal complexes with thiosemicarbazones

1‐phenyl‐3‐methyl‐4‐benzoyl‐5‐pyrazolone 4‐ethyl‐thiosemicarbazone (HL) and its copper(II), vanadium(V) and nickel(II) complexes: [Cu(L)(Cl)]·C₂H₅OH·( 1 ), [Cu(L)₂]·H₂O ( 2 ), [Cu(L)(Br)]·H₂O·CH₃OH ( 3 ), [Cu(L)(NO₃)]·2C₂H₅OH ( 4 ), [VO₂(L)]·2H₂O ( 5 ), [Ni(L)₂]·H₂O ( 6 ), were synthesized and characterized. The ligand has been characterized by elemental analyses, IR, ¹H NMR and ¹³C NMR spectroscopy. The tridentate nature of the ligand is evident from the IR spectra. The copper(II), vanadium(V) and nickel(II) complexes have been characterized by different physico‐chemical techniques such as molar conductivity, magnetic susceptibility measurements and electronic, infrared and electron paramagnetic resonance spectral studies. The structures of the ligand and its copper(II) ( 2 , 4 ), and vanadium(V) ( 5 ) complexes have been determined by single‐crystal X‐ray diffraction. The composition of the coordination polyhedron of the central atom in 2 , 4 and 5 is different. The tetrahedral coordination geometry of Cu was found in complex 2 while in complex 4 , it is square planar, in complex 5 the coordination polyhedron of the central ion is distorted square pyramid. The in vitro antibacterial activity of the complexes against Escherichia coli, Salmonella abony, Staphylococcus aureus, Bacillus cereus and the antifungal activity against Candida albicans strains was higher for the metal complexes than for free ligand. The effect of the free ligand and its metal complexes on the proliferation of HL‐60 cells was tested.     

Biventricular / left ventricular pacing in hypertrophic obstructive cardiomyopathy: an overview

Hypertrophic cardiomyopathy (HCM) is an autosomal dominant inherited genetic disease characterized by compensatory pathological left ventricle (LV) hypertrophy due to sarcomere dysfunction. In an important proportion of patients with HCM, the site and extent of cardiac hypertrophy results in severe obstruction to LV outflow tract (LVOT), contributing to disabling symptoms and increasing the risk of sudden cardiac death (SCD). In patients with progressive and/or refractory symptoms despite optimal pharmacological treatment, invasive therapies that diminish or abolish LVOT obstruction relieve heart failure-related symptoms, improve quality of life and could be associated with long-term survival similar to that observed in the general population. The gold standard in this respect is surgical septal myectomy, which might be supplementary associated with a reduction in SCD. Percutaneous techniques, particularly alcohol septal ablation (ASA) and more recently radiofrequency (RF) septal ablation, can achieve LVOT gradient reduction and symptomatic benefit in a large proportion of HOCM patients at the cost of a supposedly limited septal myocardial necrosis and a 10-20% risk of chronic atrioventricular block. After an initial period of enthusiasm, standard DDD pacing failed to show in randomized trials significant LVOT gradient reductions and objective improvement in exercise capacity. However, case reports and recent small pilot studies suggested that atrial synchronous LV or biventricular (biV) pacing significantly reduce LVOT obstruction and improve symptoms (acutely as well as long-term) in a large proportion of severely symptomatic HOCM patients not suitable to other gradient reduction therapies. Moreover, biV/LV pacing in HOCM seems to be associated with significant LV reverse remodelling.     

Genetics of symbiosis in Lotus japonicus: recombinant inbred lines, comparative genetic maps, and map position of 35 symbiotic loci

Development of molecular tools for the analysis of the plant genetic contribution to rhizobial and mycorrhizal symbiosis has provided major advances in our understanding of plant-microbe interactions, and several key symbiotic genes have been identified and characterized. In order to increase the efficiency of genetic analysis in the model legume Lotus japonicus, we present here a selection of improved genetic tools. The two genetic linkage maps previously developed from an interspecific cross between L. japonicus Gifu and L. filicaulis, and an intraspecific cross between the two ecotypes L. japonicus Gifu and L. japonicus MG-20, were aligned through a set of anchor markers. Regions of linkage groups, where genetic resolution is obtained preferentially using one or the other parental combination, are highlighted. Additional genetic resolution and stabilized mapping populations were obtained in recombinant inbred lines derived by a single seed descent from the two populations. For faster mapping of new loci, a selection of reliable markers spread over the chromosome arms provides a common framework for more efficient identification of new alleles and new symbiotic loci among uncharacterized mutant lines. Combining resources from the Lotus community, map positions of a large collection of symbiotic loci are provided together with alleles and closely linked molecular markers. Altogether, this establishes a common genetic resource for Lotus spp. A web-based version will enable this resource to be curated and updated regularly.     

Phenotypic and molecular identification of a novel thermophilic Anoxybacillus species: a lipase-producing bacterium isolated from a Malaysian hotspring

Eleven lipase-producing thermophilic bacteria strains were recently isolated from Kuala Woh Hot Spring, in Peninsular Malaysia. These strains have been qualitatively screened using Rhodamine B-olive oil plate agar. All strains showed lipase activity in the range of 0.56–2.62 U/ml. Their thermostabilities were then determined by incubation at 80°C for 30 min. Results showed that strain KW 6 and KW 12 produced relatively thermostable lipases, which retained 62 and 54% of their original activity, respectively. They were identified based on their morphological characteristics, biochemical tests and the Biolog system. Strain KW 12 showed exceptionally unique characteristics (over KW 6) being able to grow in a broad range of pH and temperature. It was further identified using 16S rRNA partial sequence analysis and the result of 16S rRNA partial sequence analysis identified KW 12 as Anoxybacillus kamchatkensis.     

Virulotyping of <Emphasis Type="Italic">Salmonella enterica</Emphasis> subsp. <Emphasis Type="Italic">enterica</Emphasis> isolated from indigenous vegetables and poultry meat in Malaysia using multiplex-PCR

The increased occurrence of Salmonella occurrence in local indigenous vegetables and poultry meat can be a potential health hazards. This study is aimed to detect the prevalence of twenty different virulence factors among Salmonella enterica strains isolated from poultry and local indigenous vegetables in Malaysia via an optimized, rapid and specific multiplex PCR assay. The assay encompasses a total of 19 Salmonella pathogenicity islands genes and a quorum sensing gene (sdiA) in three multiplex reaction sets. A total of 114 Salmonella enterica isolates belonging to 38 different serovars were tested. Each isolate in under this study was found to possess up to 70% of the virulence genes tested and exhibited variable pathogenicity gene patterns. Reproducibility of the multiplex PCR assay was found to be 100% and the detection limit of the optimized multiplex PCR was tested with lowest detectable concentration of DNA 0.8 pg μl⁻¹. This study demonstrated various Salmonella pathogenicity island virulence gene patterns even within the same serovar. This sets of multiplex PCR system provide a fast and reliable typing approach based on Salmonella pathogenicity islands, thus enabling an effective monitoring of emerging pathogenic Salmonella strains as an additional tool in Salmonella surveillance studies.     

Identity-by-Descent Matrix Decomposition Using Latent Ancestral Allele Models

Genetic linkage and association studies are empowered by proper modeling of relatedness among individuals. Such relatedness can be inferred from marker and/or pedigree information. In this study, the genetic relatedness among n inbred individuals at a particular locus is expressed as an n × n square matrix Q. The elements of Q are identity-by-descent probabilities, that is, probabilities that two individuals share an allele descended from a common ancestor. In this representation the definition of the ancestral alleles and their number remains implicit. For human inspection and further analysis, an explicit representation in terms of the ancestral allele origin and the number of alleles is desirable. To this purpose, we decompose the matrix Q by a latent class model with K classes (latent ancestral alleles). Let P be an n × K matrix with assignment probabilities of n individuals to K classes constrained such that every element is nonnegative and each row sums to 1. The problem then amounts to approximating Q by PP^T, while disregarding the diagonal elements. This is not an eigenvalue problem because of the constraints on P. An efficient algorithm for calculating P is provided. We indicate the potential utility of the latent ancestral allele model. For representative locus-specific Q matrices constructed for a set of maize inbreds, the proposed model recovered the known ancestry.HIGH-THROUGHPUT techniques allow extensive genotyping of individuals for thousands of SNP markers (Gibbs et al. 2003) and thereby provide accurate information about the genetic diversity within a population at many chromosomal loci. If two individuals within this population carry the same DNA sequence at a locus, and this sequence can be traced to the same common ancestor, the individuals are said to be identical by descent (IBD) for this segment (Chapman and Thompson 2003). Quite often, however, the ancestral source of a chromosomal segment is ambiguous and thus IBD relationships between haplotypes are given as probabilities. Various methods have been described to estimate the IBD probability of pairs of chromosomal segments (Meuwissen and Goddard 2001; Leutenegger et al. 2003). When pedigree relationships are known, these can be included to estimate IBD probabilities (Wang et al. 1995; Heath 1997; George et al. 2000; Meuwissen and Goddard 2000; Besnier and Carlborg 2007).In quantitative genetic analysis we seek to find and characterize associations between the large number of SNPs that are now available for many organisms and phenotypic variation for traits of interest (e.g., grain yield and time to flowering). Many current methods developed for this purpose make use of IBD information. For example, a locus-specific matrix of IBD probabilities can be incorporated into restricted maximum-likelihood (REML) procedures for fine mapping quantitative trait loci (Bink and Meuwissen 2004) as well as for marker-based genetic evaluation (Fernando and Grossman 1989) using mixed models. The IBD matrix takes the role of a covariance matrix in the REML procedure.Other approaches, however, require that chromosome segments (also referred to here as haplotypes or alleles) are assigned to independent ancestors. These approaches include regression approaches with genetic predictors (Malosetti et al. 2006) and Bayesian oligo-allelic approaches that sample the ancestral origin of each chromosomal segment (Heath 1997; Uimari and Sillanpaa 2001; Bink et al. 2008a). In the IBD matrix representation the ancestral alleles and their number remain implicit. For these approaches, the locus-specific matrix of IBD probabilities must therefore be decomposed into a matrix that links the chromosomal segments to independent ancestral alleles. This decomposition is addressed in this article.The individuals that we consider in this article are inbred. For n inbred individuals the IBD matrix at a given chromosomal position is thus n × n, because there is no need to distinguish between identical chromosomes. In diploid, outbred populations, each individual would be represented by two haplotypes (alleles) and the matrix would be 2n × 2n (Fernando and Grossman 1989). This is feasible if any phase ambiguity can be resolved. From now on, the term “individual” thus means chromosomal segment or haplotype. Analogously, ancestor will be shorthand for ancestral allele (ancestral haplotype).We propose two models of IBD matrix decomposition, a simple threshold model (TIBD) and a more sophisticated latent ancestral allele model (LAAM), that provide (1) an estimate of the number of independent ancestral alleles, (2) a concise, easy-to-interpret, summary of the relatedness, (3) an explicit (probabilistic) representation of the descent of alleles, and (4) the ability to sample alleles for each individual from a set of ancestral alleles in such a way that the probability that a pair of individuals shares the same allele corresponds to their IBD probability.The last two features of the model are essential for its use in Bayesian oligo-allelic approaches to quantitative trait locus (QTL) analysis (Uimari and Sillanpaa 2001; Bink et al. 2008a).