Oxovanadium(IV) and oxovanadium(V) complexes relevant to biological systems

A novel method for the analysis of trace element chemical speciation at parts per billion (ppb) levels in wound fluid samples both contributes to the fundamental inorganic biochemistry of the healing process and permits improved treatments. Potentiometric Stripping Analysis in combination with acid digestion has been used to quantify the total copper and zinc levels in a series of 0.5 ml samples of fluid obtained from surgical wounds. Further, the degree of blood contamination has been investigated using visible spectroscopy. The prevailing chemical speciation (chemical forms) of these total concentrations of copper and zinc amongst low molecular mass ligands in wound fluid has been investigated by computer modelling using JESS, the Joint Expert Speciation System. The model, involving 38 components, generates in the region of 3500 individual low molecular mass complexes including copper, zinc, iron, calcium and manganese species, and predicts that the majority of low molecular mass (lmm) copper complexes are electrically net-neutral, whilst those of zinc are predominantly charged. Further studies indicate that supplementing the concentrations of histidine and tryptophan may increase the net-neutral zinc fraction, the optimum effect being achieved at pH=7.4. This may be important in transporting zinc into healing cells.     

Spectroscopic and magnetic properties of a Ni(II) complex with citric acid

The complex compound K₂[Ni(cit)(H₂O)₂]₂·4H₂O (cit = triionized citrate ion) seems to be a good model for the investigation of Ni(II)/citrate interactions that are of interest in relation to nickel metabolism and bioaccumulation. Its infrared and Raman spectra were recorded and analyzed on the basis of its structural peculiarities. The magnetic susceptibility, investigated in the temperature range between 1.9 and 300 K, shows the absence of magnetic interactions between the two metal centers present in this structure.     

Capillary blood flow imaging within human finger cuticle using optical microangiography

We report non‐invasive 3D imaging of capillary blood flow within human finger cuticle by the use of Doppler optical microangiography (DOMAG) and ultra‐high sensitive optical microangiography (UHS‐OMAG) techniques. Wide velocity range DOMAG method is applied to provide red blood cell (RBC) axial velocity mapping in capillary loops with ranges of ±0.9 mm/s and ±0.3 mm/s. Additionally, UHS‐OMAG technique is engineered to acquire high resolution image of capillary morphology. The presented results are promising to facilitate clinical trials of treatment and diagnosis of various diseases such as diabetes, Raynaud's phenomenon, and connective tissue diseases by quantifying cutaneous blood flow changes within human finger cuticle. (© 2013 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)     

Structural investigation of the glandular trichomes of <Emphasis Type="Italic">Salvia argentea</Emphasis>

The morphology, anatomy and distribution of glandular trichomes on the aerial organs of Salvia argentea L. has been investigated. Two morphologically distinct types of glandular trichomes were determined. Capitate glandular trichomes forming a base 1–7 celled, a stalk 1–5 celled or no stalk and a head uni- or bicellular had various types. In capitate trichomes, the neck cell that has an important role especially for xeroformic plants, acting to prevent the backflow of secreted substance through the apoplast has been distinctively observed in the investigated species. The capitate trichomes were present abundantly on all aerial organs of S. argentea. Peltate glandular trichomes had a large secretory head forming 1–5, 8 central and 8–10, 12, 14 peripheral cells. Peltate trichomes are present on all aerial organs, except petiole, being the most abundant on calyx and corolla. Results were shown by tables and photographs.     

Visualization of three-way comparisons of omics data

Background  

Density plot visualizations (also referred to as heat maps or color maps) are widely used in different fields including large-scale omics studies in biological sciences. However, the current color-codings limit the visualizations to single datasets or pairwise comparisons.     

Age-related increase of kynurenic acid in human cerebrospinal fluid - IgG and beta2-microglobulin changes

Kynurenic acid (KYNA) is an endogenous metabolite in the kynurenine pathway of tryptophan degradation and is an antagonist at the glycine site of the N-methyl-D-aspartate as well as at the alpha 7 nicotinic cholinergic receptors. In the brain tissue KYNA is synthesised from L-kynurenine by kynurenine aminotransferases (KAT) I and II. A host of immune mediators influence tryptophan degradation. In the present study, the levels of KYNA in cerebrospinal fluid (CSF) and serum in a group of human subjects aged between 25 and 74 years were determined by using a high performance liquid chromatography method. In CSF and serum KAT I and II activities were investigated by radioenzymatic assay, and the levels of beta(2)-microglobulin, a marker for cellular immune activation, were determined by ELISA. The correlations between neurochemical and biological parameters were evaluated. Two subject groups with significantly different ages, i.e. <50 years and >50 years, p < 0.001, showed statistically significantly different CSF KYNA levels, i.e. 2.84 +/- 0.16 fmol/microl vs. 4.09 +/- 0.14 fmol/microl, p < 0.001, respectively; but this difference was not seen in serum samples. Interestingly, KYNA is synthesised in CSF principally by KAT I and not KAT II, however no relationship was found between enzyme activity and ageing. A positive relationship between CSF KYNA levels and age of subjects indicates a 95% probability of elevated CSF KYNA with ageing (R = 0.6639, p = 0.0001). KYNA levels significantly correlated with IgG and beta(2)-microglobulin levels (R = 0.5244, p = 0.0049; R = 0.4253, p = 0.043, respectively). No correlation was found between other biological parameters in CSF or serum. In summary, a positive relationship between the CSF KYNA level and ageing was found, and the data would suggest age-dependent increase of kynurenine metabolism in the CNS. An enhancement of CSF IgG and beta(2)-microglobulin levels would suggest an activation of the immune system during ageing. Increased KYNA metabolism may be involved in the hypofunction of the glutamatergic and/or nicotinic cholinergic neurotransmission in the ageing CNS.     

Re-localization of nuclear DNA helicase II during the growth period of bovine oocytes

Nuclear DNA helicase II (NDH II) is the bovine homolog of human RNA helicase A. The aim of this study was to compare NDH II localization between somatic cells (bovine embryonal fibroblasts) and female germ cells (oocytes), with the main focus on the dynamic changes in the redistribution of NDH II during the growth phase of the bovine oocytes. The fine granular staining of NDH II was spread in the whole nucleoplasm of fibroblasts, excluding the reticulated nucleoli. In contrast, the large reticulated nucleoli of the growing oocytes isolated from early antral follicles exhibited strong positivity for NDH II together with the immunostaining signals of upstream binding factor (UBF) and RNA polymerase I subunit (PAF53), documenting the high synthetic activity of these nucleoli. At the time of termination of oocyte growth, NDH II was preferentially located at the nucleolar periphery together with proteins of fibrillar centres. In fully grown oocytes, NDH II was still present in the thin periphery shell around the compact nucleolar core. The semiquantitative RT-PCR revealed that the average signal of NDH II mRNA in fully grown oocytes was only at 40% level in comparison with growing oocytes. Western blot analysis further confirmed that a 140 kD NDH II protein was abundant in growing oocytes, while the signal was substantially weaker in fully grown oocytes. The significant decrease in NDH II gene expression and in NDH II mRNA translation correlates with a termination of the oocyte growth. Altogether, the results demonstrate that NDH II expression parallels the activity of ribosomal RNA biosynthesis in the bovine growing oocytes.     

Influence of reduction of heme a and Cu(A) on the oxidized catalytic center of cytochrome c oxidase: insight from organic solvents

Purified bovine heart cytochrome c oxidase (CcO) has been extracted from aqueous solution into hexane in the presence of phospholipids and calcium ions. In extracts, CcO is in the so-called "slow" form and probably situated in reverse micelles. At low water:phospholipid molar ratios, electron transfer from reduced heme a and Cu(A) to the catalytic center is inhibited and both heme a3 and Cu(B) remain in the oxidized state. The rate of binding of cyanide to heme a3 in this oxidized catalytic center is, however, dependent on the redox state of heme a and Cu(A). When heme a and Cu(A) are reduced, the rate is increased 20-fold compared to the rate when these two centers are oxidized. The enhanced rate of binding of cyanide to heme a3 is explained by the destabilization of an intrinsic ligand, located at the catalytic site, that is triggered by the reduction of heme a and Cu(A).     

Synthesis, characterization, and biological activity of oxovanadium(IV) complexes with polyalcohols

Oxovanadium(IV) complexes of the polyalcohols sorbitol, galactitol, and mannitol, of stoichiometry Na(2)[VO(L)(2)].H(2)O, were obtained from aqueous alkaline solutions. They were characterized by elemental analysis, infrared and UV-vis spectroscopies, thermoanalytical (thermogravimetric and differential thermal analysis) data, and magnetic susceptibility measurements. The biological activities of the complexes on the proliferation, differentiation, and glucose consumption were tested on osteoblast-like cells (MC3T3E1 osteoblastic mouse calvaria-derived cells and UMR106 rat osteosarcoma-derived cells) in culture. The three complexes exerted a biphasic effect on cell proliferation, being slight stimulating agents at low concentrations and inhibitory in the range of 25-100 microM. All the complexes inhibited cell differentiation in tumor osteoblasts. Their effects on glucose consumption were also discussed. The free ligands did not show any effect on the studied biological parameters.