The GLUT9 gene is associated with serum uric acid levels in Sardinia and Chianti cohorts

High serum uric acid levels elevate pro-inflammatory–state gout crystal arthropathy and place individuals at high risk for cardiovascular morbidity and mortality. Genome-wide scans in the genetically isolated Sardinian population identified variants associated with serum uric acid levels as a quantitative trait. They mapped within GLUT9, a Chromosome 4 glucose transporter gene predominantly expressed in liver and kidney. SNP rs6855911 showed the strongest association (p = 1.84 × 10⁻¹⁶), along with eight others (p = 7.75 × 10⁻¹⁶ to 6.05 × 10⁻¹¹). Individuals homozygous for the rare allele of rs6855911 (minor allele frequency = 0.26) had 0.6 mg/dl less uric acid than those homozygous for the common allele; the results were replicated in an unrelated cohort from Tuscany. Our results suggest that polymorphisms in GLUT9 could affect glucose metabolism and uric acid synthesis and/or renal reabsorption, influencing serum uric acid levels over a wide range of values.     

Differential responsiveness to immunoablative therapy in refractory rheumatoid arthritis is associated with level and avidity of anti-cyclic citrullinated protein autoantibodies: a case study

In order to identify pathogenic correlates of refractory rheumatoid arthritis (RA), antibodies against anti-cyclic citrullinated protein (ACPAs) were investigated in RA patients in whom the dysregulated immune system had been ablated by high-dose chemotherapy (HDC) and autologous haematopoietic stem cell transplantation (HSCT). Six patients with refractory RA were extensively characterized in terms of levels of total immunoglobulins, RA-specific autoantibodies (ACPAs and rheumatoid factor) and antibodies against rubella, tetanus toxoid (TT) and phosphorylcholine before and after HDC plus HSCT. Additionally, the avidity of ACPAs was measured before and after treatment and compared with the avidity of TT antibodies following repeated immunizations. Synovial biopsies were obtained by arthroscopy before HDC plus HSCT, and analyzed by immunohistochemistry. In the three patients with clinically long-lasting responses to HDC plus HSCT (median 423 days), significant reductions in ACPA-IgG levels after therapy were observed (median level dropped from 215 to 34 arbitrary units/ml; P = 0.05). In contrast, stable ACPA-IgG levels were observed in three patients who relapsed shortly after HDC plus HSCT (median of 67 days). Clinical responders had ACPA-IgG of lower avidity (r = 0.75; P = 0.08) and higher degree of inflammation histologically (r = 0.73; P = 0.09). Relapse (after 38 to 530 days) in all patients was preceded by rising levels of low avidity ACPA-IgG (after 30 to 388 days), in contrast to the stable titres of high avidity TT antibodies. In conclusion, humoral autoimmune responses were differentially modulated by immunoablative therapy in patients with synovial inflammation and low avidity ACPA-IgG autoantibodies as compared with patients with high levels of high avidity ACPA-IgG. The distinct clinical disease course after immunoablative therapy based on levels and avidity of ACPA-IgG indicates that refractory RA is not a single disease entity.     

HPRTSardinia: a new point mutation causing HPRT deficiency without Lesch-Nyhan disease

Hypoxanthine-guanine phosphoribosyltransferase (HPRT) deficiency always causing hyperuricemia presents various degrees of neurological manifestations, the most severe which is Lesch-Nyhan syndrome. The HPRT gene is situated in the region Xq26-q27.2 and consists of 9 exons. At least 300 different mutations at different sites in the HPRT coding region from exon 1 to exon 9 have been identified. A new mutation in the HPRT gene has been determined in one patient with complete deficiency of erythrocyte activity, with hyperuricemia and gout but without Lesch-Nyhan disease. Analysis of cultured fibroblasts revealed minimal residual HPRT activity mainly when guanine was the substrate. Genomic DNA sequencing demonstrated patient's mother heterozygosity for the mutation and no mutation in her brother. The mutation consists in a C-->T transversion at cDNA base 463 (C463T) in exon 6, resulting in proline to serine substitution at codon 155 (P155S). This mutation had not been reported previously and has been designated HPRT(Sardinia). The mutation identified in this patient allows some expression of functional enzyme in nucleated cells such as fibroblasts, indicating that such cell type may add further information to conventional blood analysis. A multicentre survey gathering patients with variant neurological forms could contribute to understand the pathophysiology of the neurobehavioral symptoms of HPRT deficiency.     

Structural studies on zinc(II) complexes with 2-benzoylpyridine-derived hydrazones

2-Benzoylpyridine-phenylhydrazone (H2BzPh), 2-benzoylpyridine-para-chloro-phenylhydrazone (H2BzpClPh), and 2-benzoylpyridine-para-nitro-phenyl (H2BzpNO₂Ph) hydrazone were obtained and fully characterized, as well as their zinc(II) complexes [Zn(H2BzPh)Cl₂] (1), [Zn(H2BzClPh)Cl₂] (2) and [Zn(H2BzpNO₂Ph)Cl₂] (3). During the syntheses of complex 1 a second product crystallized, which was characterized as [Zn(2BzPh)₂] (1a). Upon re-crystallization in 1:9 DMSO:acetone conversion of 2 into [Zn(H2BzpClPh)Cl₂] · H₂O (2a) and of 3 into [Zn(2BzpNO₂Ph)Cl(DMSO)] (3a) occurred. The crystal structures of 1a, 2a and 3a were determined. In 1a the two nearly perpendicular H2BzPh ligands give rise to a distorted octahedral environment around the metal. The 5-fold coordination around the metal is completed with two chloride ions in 2a and with one chloride and one oxygen atom from DMSO in 3a.     

A multi-layer method to study genome-scale positions of nucleosomes

The basic unit of eukaryotic chromatin is the nucleosome, consisting of about 150 bp of DNA wrapped around a protein core made of histone proteins. Nucleosomes position is modulated in vivo to regulate fundamental nuclear processes. To measure nucleosome positions on a genomic scale both theoretical and experimental approaches have been recently reported. We have developed a new method, Multi-Layer Model (MLM), for the analysis of nucleosome position data obtained with microarray-based approach. The MLM is a feature extraction method in which the input data is processed by a classifier to distinguish between several kinds of patterns. We applied our method to simulated-synthetic and experimental nucleosome position data and found that besides a high nucleosome recognition and a strong agreement with standard statistical methods, the MLM can identify distinct classes of nucleosomes, making it an important tool for the genome wide analysis of nucleosome position and function. In conclusion, the MLM allows a better representation of nucleosome position data and a significant reduction in computational time.     

Macronutrients requirements of the dinoflagellate Protoceratium reticulatum

The basal L1 medium was found to be unsatisfactory for culturing the red tide dinoflagellate Protoceratium reticulatum at a high growth rate and biomass yield. The L1 medium enhanced with phosphate to a total concentration of 217 μM supported the highest attainable growth rate and biomass yield. Once the phosphate concentration exceeded 6× L1, phosphate inhibited the dinoflagellate growth and negatively affected cell viability. At the optimal phosphate concentration of 217 μM, an increase in nitrate concentration over the range of 882–8824 μM, did not affect cell growth and yield. Nitrate did not inhibit growth at any of the concentrations used. Clearly, the basal nitrate level in L1 is sufficient for effectively culturing P. reticulatum. At the ranges of phosphate and nitrate concentrations tested, cell volume was not sensitive to the concentration of nutrients but the concentration of phosphate affected both the specific cell number and cell volume growth rates. Elevated levels of nutrients supported their intracellular accumulation. Cell-specific production of yessotoxin was not influenced by concentration of phosphate in the culture medium, but elevated (>1764 μM) nitrate concentration did enhance the yessotoxin level. Phosphate concentration that maximized biomass yield also maximized volumetric production of yessotoxin in the culture broth.     

Identification of chalcones as in vivo liver monofunctional phase II enzymes inducers

Cancer preventive agents (CPA) are drugs able to suppress the carcinogen metabolic activation or block the formation of ultimate carcinogens. CPA could act through various molecular mechanisms, for example by interfering with the action of procarcinogen. This could be attained by increasing the phase II enzymes levels of quinone reductase (QR) and glutathione S-transferase (GST). New flavonoids, especially chalcones, have been identified as in vivo monofunctional phase II enzymes inducers. Oral administration of chalcone, 4, and both p-methoxy-substituted chalcones, 6 and 14, increased hepatic QR activity with concomitant decrease in CYP1A1 activity, a member of the most important group of phase I enzymes cytochrome P450. Among them, 4 also increased GST activity. While p-bromo-substituted chalcone 8 was the best inducer of QR it decreased hepatic GST expression and cytochrome P450, being the most effective decreasing cytochrome P450-expression. Thienyl-chalcone 20 being the bioisostere of chalcone 4 did not display the same in vivo profile in the phase I level modification. As chalcone 4 its bioisostere, chalcone 20, displayed low DNA strand breakage and absence of mutagenicity. Also, in our preliminary in vivo tumourigenesis/chemopreventive and acute-toxicity studies, chalcones 4, 6 and 8 showed the best behaviours as CPA justifying additional studies that are ongoing.     

Polarized light based scheme to monitor column performance in a continuous foam fractionation column

Background  

A polarized light scattering technique was used to monitor the performance of a continuously operated foam fractionation process. The S ₁₁ and S ₁₂ parameters, elements of the light scattering matrix, combined together (S ₁₁ +S ₁₂) have been correlated with the bubble size and liquid content for the case of a freely draining foam. The performance of a foam fractionation column is known to have a strong dependence on the bubble size distribution and liquid hold up in foam. In this study the enrichment is used as a metric, representative of foam properties and column performance, and correlated to the S ₁₁ +S ₁₂ parameter.     

Mean-square displacement relationship in bioprotectant systems by elastic neutron scattering

Neutron intensity elastic scans on trehalose, maltose, and sucrose/H(2)O mixtures as a function of concentration, temperature, and exchanged wave vector are presented. The experimental findings show a crossover in molecular fluctuations between harmonic and anharmonic dynamical regimes. A new operative definition for the degree of fragility of glass-forming systems is furnished by using explicitly the connection between viscosity and mean-square displacement. The procedure is tested for the investigated mixtures and for a set of glass-forming systems. In this frame, the stronger character of trehalose/H(2)O mixture indicates a better attitude in respect to maltose and sucrose/H(2)O mixtures to encapsulate biostructures in a more rigid matrix.     

Pattern of bone markers during pregnancy and their changes after delivery

OBJECTIVE: To investigate whether bone resorption markers change during pregnancy and lactation, and how they are correlated with human placental lactogen (hPL) and PRL. SUBJECTS: Young women before pregnancy, during pregnancy and during a 12-month post-delivery period (study group; n = 22); and age- and weight-matched normal cycling women (control group; n = 22) for a 20-month-period participated in the study. RESULTS: In the study group, women both during pregnancy (from the 8th up to the 38th week) and during a 6-month period of lactation, pyridinoline and deoxypyridinoline urinary levels were significantly higher than those of pre-pregnancy and control women. They returned to basal values at the 12th post-delivery month. During pregnancy there were early and late peak increases, at the 8th and 32nd week, respectively. At the 32nd, 34th, 36th and 38th week of pregnancy, pyridinoline and deoxypyridinoline urinary values were significantly correlated with hPL serum levels. CONCLUSIONS: During pregnancy the maternal bone resorption seems to vary critically at early and late stages. A complete reversal of these variations seems to occur after lactation. Further studies could evaluate if changes in placental function are capable of differently interfering with maternal bone resorption.