Immobilized Alkaline Phosphatase for Molecular Cloning

Alkaline phosphatase from E. coli was immobilized on Sepharose-4B, macroporous cellulose and chitosan-based carriers. The yields of immobilization were over 60% in most cases. It was shown that immobilized alkaline phosphatase can be used for dephosphorylation of DNA 5'-termini.     

A shell finite element model of the pelvic floor muscles

The pelvic floor gives support to the organs in the abdominal cavity. Using the dataset made public in (Janda et al. J. Biomech. (2003 Janda, S., van der Helm, F.C.T. and de Blok, B. 2003. Measuring morphological parameters of the pelvic floor for finite element modelling purposes. J. Biomech., 36(6): 749–757. [Crossref] , [Google Scholar]) 36(6), pp. 749–757), we have reconstructed the geometry of one of the most important parts of the pelvic floor, the levator ani, using NURB surfaces. Once the surface is triangulated, the corresponding mesh is used in a finite element analysis with shell elements.

Based on the 3D behavior of the muscle we have constructed a shell that takes into account the direction of the muscle fibers and the incompressibility of the tissue. The constitutive model for the isotropic strain energy and the passive strain energy stored in the fibers is adapted from Humphrey's model for cardiac muscles. To this the active behavior of the skeletal muscle is added.

We present preliminary results of a simulation of the levator ani muscle under pressure and with active contraction. This research aims at helping simulate the damages to the pelvic floor that can occur after childbirth.     

Nasal mites (Gamasida: Rhinonyssidae) of Paroaria coronata (Miller) (Passeriformes: Emberezidae)

With the aim of identifying the species of nasal mites of Paroaria coronata (red-crested cardinal), the nasal cavity of 40 birds were examined. The nasal mites were identified as Ptilonyssus sairae de Castro and Sternostoma pirangae Pence, with 50% and 7.5% of prevalence, respectively. This is the first record of these mite species parasitizing P. coronata. This report also amplifies the area of occurrence of S. pirangae for Brazil and that of P. sairae for Rio Grande do Sul, Brazil.     

Molecular diversity of small balsam populations in relation to site characteristics

Climatic shifts within recent decades created favorable conditions for invasive species flourishing in more Northern parts of Europe. Our study was aimed at evaluation of genetic variability and habitat features of Impatiens parviflora populations growing in Lithuania. Twenty one populations were selected and analysed using simple sequence repeat (SSR) and randomly amplified polymorphic DNA (RAPD) assays. Evaluated by SSRs, 315 individuals were all monomorphic and homozygous at 4 loci and heterozygous at 1 locus. RAPD analyses revealed that the percentage of polymorphic DNA loci (% P) per population ranged from 7 to 39% and genetic differentiation between populations was Φ_PT=0.790 (P<0.01). Genetic distances among populations (0.135–0.426) correlated significantly with geographical distances (r=0.183; P<0.008). Populations in overmoistured soil contained higher % P (28.3) when compared to drier soil (18.7; P<0.05). All recorded populations were close to roads; their % P did not depend on proximity to buildings, light intensity or population size. Our RAPD analyses indicate multiple introductions of this species in Lithuania. Analyses of I. parviflora at SSR and RAPD loci show that the invasion process is reflected in genetic structure.     

Drivers of plant species composition in alder-dominated forests with contrasting connectivity

The effects of local and regional environmental variables as well as spatial gradients on the plant species composition of two types of alder-dominated forests (riparian forests and alder carrs) with contrasting connectivity were studied across the Western Carpathians from Hungary through Slovakia to Poland. We used large vegetation (240 sampling plots) and environmental (24 variables) datasets, which were accompanied by spatial variables represented by principal coordinates of neighbour matrices. Canonical correspondence analysis (CCA) of the two datasets revealed 13 and 29 variables with significant effects on variation in species composition of alder carrs and riparian alder forests, which jointly explained 41.2% and 36.4% of the variability, respectively. Altitude was the most important factor explaining 7.7% of the variability in the species composition of alder carrs and 8.2% in riparian alder forests. Variation partitioning in CCA revealed that local variables were crucial drivers for species composition patterns in alder carrs, while spatial processes unrelated to the measured environmental variables shaped the vegetation structure of riparian forests.

     

Three unusual but cytogenetically similar cases with up to five different cell lines involving structural and numerical abnormalities of chromosome 18.

We report two prenatal and two postnatal diagnosed cases (the latter monozygotic twins) with ring chromosomes after GTG banding. All four, de novo r(18), cases turned out to be more complex after application of high-resolution molecular cytogenetics techniques such as use of fluorescence in situ hybridization, centromeric probes, multicolor banding, and locus-specific probes for chromosome 18. All four cases are mosaics involving chromosome 18 in up to five different cell lines, including 46,r(18); 46,dr(18); 47,r(18)x2; 46,mar(18); and 45,-18. Mosaicism sharing both numerical and structural anomalies is rare, but rings often appear as mosaics due to their mitotic instability. Overall, patients with ring chromosome 18 usually share clinical features of 18q- syndrome and, less frequently, those of 18p- syndrome. High-resolution molecular cytogenetics techniques were useful in the characterization of cases with dynamic mosaicism and in establishing the relationship between loss or gain of chromosomal material and the phenotype.     

Repression of intracellular virulence factors in Salmonella by the Hha and YdgT nucleoid-associated proteins

The Hha/YmoA family of nucleoid-associated proteins is involved in gene regulation in enterobacteria. In Salmonella enterica serovar Typhimurium, virulence genes required for intracellular growth are induced following host cell invasion but the proteins responsible for repressing these genes prior to host cell entry have not been fully identified. We demonstrate here that Hha is the major repressor responsible for silencing virulence genes carried in Salmonella pathogenicity island 2 prior to bacteria sensing an intracellular environmental cue.     

Amino acid toxicities of Escherichia coli that are prevented by leucyl-tRNA synthetase amino acid editing

Leucyl-tRNA synthetase (LeuRS) has evolved an editing function to clear misactivated amino acids. An Escherichia coli-based assay was established to identify amino acids that compromise the fidelity of LeuRS and translation. Multiple nonstandard as well as standard amino acids were toxic to the cell when LeuRS editing was inactivated.     

Physicochemical characterization of deflazacort: thermal analysis, crystallographic and spectroscopic study

The solid state properties of deflazacort (1-(1beta,16alpha)-21-(acetyloxy)-11-hydroxy-2'-methyl-5'H-pregna-1,4-dieno[17,16-d]oxazole-3,20-dione, 1) were investigated using differential scanning calorimetry (DSC), thermogravimetry (TG), single-crystal X-ray diffraction, solid and liquid nuclear magnetic resonance spectroscopy ((13)C NMR), Fourier transform infrared and Raman spectroscopy (FTIR and FT Raman). From the trends observed in the crystal structure and spectral data some conclusions can be made about hydrogen bonding, molecular conformation and crystal packing. Compound 1 crystallizes in an orthorhombic cell, space group P2(1)2(1)2(1) and the following lattice parameters: a=11.2300(5), b=12.8161(8), c=16.171(1)A, V: 2327.4(2)A(3), D(c): 1.260g/cm(3), R1=0.0479, wR2=0.1012. The crystal structure is stabilized by intra and intermolecular interactions, which provides for a very closely packed form. The NMR data indicated that 1 shows a similar conformation in solid and liquid state; while, thermal data revealed that 1 follows a monophasic pattern with a DSC melting peak at 258.4 degrees C (DeltaH 99.7Jg(-1), n=3), indicating that 1 is thermally stable as solid; but, as liquid is unstable to undergo a thermal decomposition reaction. The reactivity of 1 toward light and moisture was examined via DSC and TLC. The data indicated that 1 do not interact with water to give hydrated forms or decomposition products; however, light degrades 1.