Synthesis, crystal structure, magnetic properties, and electronic structure of the new ternary vanadate CuMnVO4.

A new magnetic oxide, CuMnVO4, was prepared, and its crystal structure was determined by single-crystal X-ray diffraction. The magnetic properties of CuMnVO4 were characterized by magnetic susceptibility and specific heat measurements, and the spin exchange interactions of CuMnVO4 were analyzed on the basis of spin-polarized electronic band structure calculations. CuMnVO4 contains MnO4 chains made up of edge-sharing MnO6 octahedra containing high-spin Mn2+ cations.

Band filling and interband scattering effects in MgB2: carbon versus aluminum doping.

We argue, based on band structure calculations and the Eliashberg theory, that the observed decrease of T(c) of Al and C doped MgB2 samples can be understood mainly in terms of a band filling effect due to the electron doping by Al and C. A simple scaling of the electron-phonon coupling constant lambda by the variation of the density of states as a function of electron doping is sufficient to capture the experimentally observed behavior. Further, we also explain the long standing open question of the experimental observation of a nearly constant pi gap as a function of doping by a compensation of the effect of band filling and interband scattering.

Vitamin D treatment of senescence accelerated mice (SAM-P/6) induces several regulators of stromal cell plasticity.

In an attempt to understand the regulation of bone marrow multipotential cells plasticity in vivo, we treated 4-month-old SAM-P/6 mice with a constant infusion of either 18 pmol/24 h of 1,25(OH)2D3 or vehicle alone for 6 weeks. In vehicle treated animals 78% +/- 4 adipose volume vs. total volume was stained positive with oil red O as compared to only 32 +/- 3% in 1,25(OH)2D3 treated animals (P < 0.

1,25(OH)2D3 acts as a bone-forming agent in the hormone-independent senescence-accelerated mouse (SAM-P/6).

Recent studies suggest that vitamin D signaling regulates bone formation. However, the overall effect of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] on bone turnover in vivo is still unclear. In this study, our aim was to examine the effect of 1,25(OH)2D3 on bone turnover in SAM-P/6, a hormone-independent mouse model of senile osteoporosis characterized by a decrease in bone formation.

A near-infrared Fourier transform Raman spectroscopy of epidermal keratinocytes: changes in the protein-DNA structure following malignant transformation.

We report here the use of near-infrared (NIR) Fourier transform (FT) Raman spectroscopy to analyze normal human epidermal keratinocytes prior to and following malignant transformation. Our analysis indicates specific Raman spectral differences between immortalized (HPK1A) and malignant ras transformed (HPK1A-ras) cells. In addition, striking spectral differences are seen in the DNA isolated from these cells and particularly in the 843/810 cm(-1) ratio with values of 1.

Glycogen storage disease type Ia in Argentina: two novel glucose-6-phosphatase mutations affecting protein stability.

Glycogen storage disease type Ia (GSD-Ia) is caused by deleterious mutations in the glucose-6-phosphatase gene (G6PC). A molecular study of this gene was carried out in 11 Argentinean patients from 8 unrelated families. Four missense (p.

Formation of complex three- and one-dimensional interpenetrating networks within carbodiimide chemistry: NCN2(-)-coordinated rare-earth-metal tetrahedra and condensed alkali-metal iodide octahedra in two novel lithium europium carbodiimide iodides, LiEu2(NCN)I3 and LiEu4(NCN)3I3.

Orange-red transparent single crystals of LiEu2(NCN)I3 and LiEu4(NCN)3I3 were synthesized from fluxes of europium iodide, sodium cyanide, sodium azide, and lithium iodide at elevated temperatures and structurally characterized by X-ray diffraction. While LiEu2(NCN)I3 crystallizes in the cubic system (Fdm, a = 15.1427(17) angstroms, V = 3472.

Identification of a common mutation in mucopolysaccharidosis IVA: correlation among genotype, phenotype, and keratan sulfate.

Mucopolysaccharidosis IVA (MPS IVA) is a lysosomal storage disorder caused by the deficiency of N-acetylgalactosamine-6-sulfate sulfatase (GALNS). Mutation screening of the GALNS was performed by genomic PCR and direct sequence analyses in 20 MPS IVA patients from Latin America. In this study, 12 different gene mutations including nine unreported ones were identified in 16 severe and four attenuated patients and accounted for 90.

[The influence of stroke laterality on coping with stroke outcome].

Objective of this study was to asses the influence of coping activities on stroke disability- and handicap-outcomes. Of special interest was to investigate if and how the variable "side of lesion" influenced the relationship between coping activities and outcomes. 105 stroke patients (50 women, 55 men, mean age 71.

Impact of genetically modified crops and their management on soil microbially mediated plant nutrient transformations.

One of the potential environmental effects of the recent rapid increase in the global agricultural area cultivated with transgenic crops is a change in soil microbially mediated processes and functions. Among the many essential functions of soil biota are soil organic matter decomposition, nutrient mineralization and immobilization, oxidation-reduction reactions, biological N fixation, and solubilization. However, relatively little research has examined the direct and indirect effects of transgenic crops and their management on microbially mediated nutrient transformations in soils.

Vitamin D inhibits Fas ligand-induced apoptosis in human osteoblasts by regulating components of both the mitochondrial and Fas-related pathways.

Apoptosis plays an important role in the regulation of bone turnover. Previously, we showed that 1,25(OH)2D3, the active form of vitamin D, may increase osteoblast survival by inhibiting apoptosis induced by serum deprivation. Human osteoblasts express the Fas receptor on their surface and its interaction with Fas ligand has been closely associated with human osteoblast apoptosis.

Ionic pair complexes with well-separated columnar stack structure based on [Pt(mnt)2]- ions showing unusual magnetic transition: syntheses, crystal structures, and magnetic properties.

Three ion pair complexes, [4-R-benzylpyridinium][bis(maleodinitriledithiolato)platinum(III)] (abbreviated as [RBzPy][Pt(mnt)(2)]; R = Cl (1), Br (2), or NO(2) (3)), have been synthesized. The cations and anions stack into well-separated columns in the solid state, and the Pt(III) ions form a 1-D zigzag chain within a [Pt(mnt)(2)](-) column through Pt..

Tetraorganylammonium superoxide compounds: close to unperturbed superoxide ions in the solid state.

Trimethylphenylammonium superoxide (1) and tetrabutylammonium superoxide (2) were prepared by ion-exchange reaction in liquid ammonia. Both compounds were structurally characterized by single-crystal X-ray diffraction. The crystal structure of 2 contains solvent ammonia molecules that are hydrogen bonded to the superoxide ion and therefore may influence the bonding properties of the superoxide ion.

A novel missense mutation, c.584A > C (Y195S), in two unrelated Argentine patients with hypoxanthine-guanine phosphoribosyl-transferase deficiency, neurological variant.

The hypoxanthine-guanine phosphoribosyl-transferase (HPRT) deficiency is an inborn error of purine metabolism, responsible for classic Lesch-Nyhan disease and its neurological and hyperuricemic variants. We report a novel mutation in the HPRT gene, c.584A > C (Y195S), in two unrelated Argentine patients affected with the neurological variant with no HPRT activity in lysed erythrocytes.

1,25(OH)2D3 inhibits bone marrow adipogenesis in senescence accelerated mice (SAM-P/6) by decreasing the expression of peroxisome proliferator-activated receptor gamma 2 (PPARgamma2).

Senile osteoporosis is the endpoint of a continuum that starts after the third decade of life when peak bone mass is attained and then is followed by a progressive and irreversible decline in bone mass. One of the mechanisms that could explain this is the increasing levels of adipogenesis in bone marrow seen with increasing age, probably due to alterations in the differentiation of mesenchymal stem cells (MSC). Senescence accelerated mice (SAM-P/6) constitute an accepted model for senile osteoporosis since their loss of bone mineral density is clearly due to high levels of adipogenesis and a deficit in osteoblastogenesis.

Synthesis and characterization of a magnetic semiconductor Na(2)RuO(4) containing one-dimensional chains of Ru(6+).

A new ternary ruthenium oxide Na(2)RuO(4) was prepared and shown to crystallize with a new structure type. Single crystal X-ray diffraction measurements reveal that Na(2)RuO(4) consists of RuO(4) chains made up of RuO(5) trigonal bipyramids by sharing axial corners. Na(2)RuO(4) is a magnetic semiconductor with a variable range hopping behavior, and its molar magnetic susceptibility chi(mol) has a broad maximum at approximately 74 K.

Inhaled and nasal corticosteroid use and the risk of fracture.

Studies of the risk of fracture associated with inhaled corticosteroids are inconclusive and are limited to short-term effects. We assessed whether long-term use increases this risk. We conducted a case control study nested within a population-based cohort of all Quebec elderly dispensed respiratory medications and followed for at least 4 years during 1988-2001.

Les malades imagines: diseases in fiction.

Writers often introduce into fiction works characters who suffer from one disease or another. The purpose of this literary finesse is to enrich the intrigue or to create a favourable environment for the observation of a group of human beings. The introduction of the sick person sometimes offers a chance to warn against venereal diseases or alcoholism or an opportunity to critize medicine and doctors.

Parathyroid hormone-related peptide and survival of patients with cancer and hypercalcemia.

Purpose: Parathyroid hormone-related peptide (PTHrP) is the predominant cause of malignancy-associated hypercalcemia. However, its prognostic utility is unclear. We aimed to determine the prognostic value of serum PTHrP levels in patients who had hypercalcemia associated with malignancy.

Genetic polymorphism of thiopurine S-methyltransferase in Argentina.

Background: Thiopurine methyltransferase (TPMT) catalyses the S-methylation of 6-thiopurine drugs, which are commonly used in the treatment of autoimmune diseases, leukaemia and organ transplantation. TPMT activity is polymorphic as a result of gene mutations. Ethnic variations in phenotype and genotype have been identified in previous population studies, but no information was available within Latin-American populations.

Pamidronate prevents the development of skeletal metastasis in nude mice transplanted with human breast cancer cells by reducing tumor burden within bone.

Pamidronate is used routinely in the treatment of established bone metastasis. However, pamidronate has not yet been assessed in the prevention of osteolytic bone metastasis and its precise mechanism of action in this disorder remains to be established. In the present study, pamidronate or vehicle alone was administered subcutaneously to nude mice either simultaneously or as post intracardiac injection of the human breast cancer MDA-MB-231 cells.

Targeted disruption of the 25-hydroxyvitamin D3 1alpha-hydroxylase gene in ras-transformed keratinocytes demonstrates that locally produced 1alpha,25-dihydroxyvitamin D3 suppresses growth and induces differentiation in an autocrine fashion.

It has been previously shown that keratinocytes express a high level of 25-hydroxyvitamin D(3) (25-OHD(3)) 1alpha-hydroxylase (1alpha-hydroxylase). 1alpha-Hydroxylase catalyzes the conversion of 25-OHD(3) to 1alpha,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)]. 1,25(OH)(2)D(3) is both antiproliferative (i.