Ciprofibrate therapy in patients with hypertriglyceridemia and low high density lipoprotein (HDL)-cholesterol: greater reduction of non-HDL cholesterol in subjects with excess body weight (The CIPROAMLAT study)

Background

Microalbuminuria and subsequent progression to proteinuria and nephropathy is associated with increased oxidative stress, increased inflammatory cytokines and increased cardiovascular (CVD) risk. The common functional IL-6 -174G>C gene variant is also associated with elevated levels of inflammatory cytokines and CVD risk.

Methods

The aim of this study was to examine the association between the IL-6 -174G>C gene variant with plasma total antioxidant status (TAOS) in 552 subjects with type 2 diabetes in relation to urinary protein excretion.

Results

In subjects free from CVD, there was a significant interaction between urinary protein excretion (normoalbuminuria/ microalbuminuria/proteinuria) and the -174C allele (compared to -174GG) in determining plasma TAOS (p value for interaction = 0.03). In the -174C allele carriers there was a significant association between plasma TAOS and urinary protein excretion: normalbuminuria v microalbuminuria v proteinuria: 44.30% ± 11.32 vs. 39.74% ± 14.83 vs. 37.93% ± 16.42, ANOVA p = 0.025. In those with CVD, no interaction or association was observed with the -174C allele (p = 0.246).

Conclusion

The IL-6 -174G>C gene variant is associated with differences in plasma oxidative stress in response to altered protein excretion in subjects with type 2 diabetes.     

Inhaled nebulized nitrite is a hypoxia-sensitive NO-dependent selective pulmonary vasodilator

The blood anion nitrite contributes to hypoxic vasodilation through a heme-based, nitric oxide (NO)-generating reaction with deoxyhemoglobin and potentially other heme proteins. We hypothesized that this biochemical reaction could be harnessed for the treatment of neonatal pulmonary hypertension, an NO-deficient state characterized by pulmonary vasoconstriction, right-to-left shunt pathophysiology and systemic hypoxemia. To test this, we delivered inhaled sodium nitrite by aerosol to newborn lambs with hypoxic and normoxic pulmonary hypertension. Inhaled nitrite elicited a rapid and sustained reduction ( approximately 65%) in hypoxia-induced pulmonary hypertension, with a magnitude approaching that of the effects of 20 p.p.m. NO gas inhalation. This reduction was associated with the immediate appearance of NO in expiratory gas. Pulmonary vasodilation elicited by aerosolized nitrite was deoxyhemoglobin- and pH-dependent and was associated with increased blood levels of iron-nitrosyl-hemoglobin. Notably, from a therapeutic standpoint, short-term delivery of nitrite dissolved in saline through nebulization produced selective, sustained pulmonary vasodilation with no clinically significant increase in blood methemoglobin levels. These data support the concept that nitrite is a vasodilator acting through conversion to NO, a process coupled to hemoglobin deoxygenation and protonation, and evince a new, simple and inexpensive potential therapy for neonatal pulmonary hypertension.     

nodD alleles of Sinorhizobium fredii USDA191 differentially influence soybean nodulation, nodC expression, and production of exopolysaccharides

All Rhizobium strains examined to date have one or multiple alleles of nodD. At least one copy of nodD and the presence of flavonoid exudates are required for nod gene induction and nodulation. Sinorhizobium fredii USDA191 has two copies of nodD. In this study, we demonstrate that inactivation of either copy of nodD caused a reduction in basal levels of expression of nodC. Extra copies of nodD1 had no effect on the expression of nodC when compared with the wild type, but extra copies of nodD2 abolished the inducer requirement, thereby rendering nodC constitutive. A nodD1 mutant was unable to nodulate soybean cultivars 'Peking' and 'McCall'. Inactivation of nodD2 or addition of extra copies of nodD1 or nodD2 caused delayed nodulation on Peking, and reduced the number of nodules on McCall. Both nodD alleles of S. fredii USDA191 appear to be involved in regulation of exopolysaccharide production; however, nodD2 appears to be more important in this respect than nodD1.     

Alternative reproduction pathway inAspergillus nidulans

Recombinant haploid segregants were recovered in filamentous fungus Aspergillus nidulans (Eidam) G. Winter directly from the heterokaryons instead of diploid segregants (process described earlier as parameiosis). In spite of the reproductive complexity of A. nidulans, parameiosis has only now been observed in this fungus. Since parameiosis was characterized by the occurrence of genetic recombination inside heterokaryotic hyphae, master strains (uvs+) and uvs mutants with high rate of both mitotic exchanges or chromosome nondisjunction were used to form heterokaryons. Two groups of mitotic segregants were recovered directly from heterokaryons--aneuploids and stable haploids. Heterokaryons formed with uvs mutants produced a higher number of parameiotic segregants compared to the heterokaryons formed with uvs+ strains. Segregants were analyzed by nutritional markers, acriflavine resistance and conidial color. Normal meiotic behavior of haploid recombinants was observed.     

Development of an enzyme-linked immunosorbent assay for detection of IgM antibodies to Babesia bigemina in cattle

A crude antigenic preparation of Babesia bigemina was used to develop an ELISA for the detection of IgM antibodies. Optimal dilutions of the antigen, using positive and negative reference sera, were determined by checkerboard titrations. Negative sera from cattle imported from tick-free areas, serum samples collected from infected B. bigemina cattle were used to validate the test. The specificity was 94% and sensitivity of the Elisa 87.5%. Sera from 385 cattle deriving from areas free from tick-borne diseases, which were submitted to a preimmunization process, were screened by this technique. The Elisa detected seroconversion on the 14th day post-inoculation in animals either infested with Boophilus microplus ticks (infected with B. bigemina), or inoculated with B. bigemina infected blood. Antibody titers decreased after day 33; however, all animals remained positive until the end of the experiment (124 days). The ELISA described may prove to be an appropriate serological test for the detection of IgM antibodies against B. bigemina.     

Inferring the history of speciation from multilocus DNA sequence data: the case of Drosophila pseudoobscura and close relatives

The divergence of Drosophila pseudoobscura from its close relatives, D. persimilis and D. pseudoobscura bogotana, was examined using the pattern of DNA sequence variation in a common set of 50 inbred lines at 11 loci from diverse locations in the genome. Drosophila pseudoobscura and D. persimilis show a marked excess of low-frequency variation across loci, consistent with a model of recent population expansion in both species. The different loci vary considerably, both in polymorphism levels and in the levels of polymorphisms that are shared by different species pairs. A major question we address is whether these patterns of shared variation are best explained by gene flow or by persistence since common ancestry. A new test of gene flow, based on patterns of linkage disequilibrium, is developed. The results from these, and other tests, support a model in which D. pseudoobscura and D. persimilis have exchanged genes at some loci. However, the pattern of variation suggests that most gene flow, although occurring after speciation began, was not recent. There is less evidence of gene flow between D. pseudoobscura and D. p. bogotana. The results are compared with recent work on the genomic locations of genes that contribute to reproductive isolation between D. pseudoobscura and D. persimilis. We show that there is a good correspondence between the genomic regions associated with reproductive isolation and the regions that show little or no evidence of gene flow.     

Specific sequences determine the stability and cooperativity of folding of the C-terminal half of tropomyosin

Tropomyosin is a flexible 410 A coiled-coil protein in which the relative stabilities of specific regions may be important for its proper function in the control of muscle contraction. In addition, tropomyosin can be used as a simple model of natural occurrence to understand the inter- and intramolecular interactions that govern the stability of coiled-coils. We have produced eight recombinant tropomyosin fragments (Tm(143-284(5OHW),) Tm(189-284(5OHW)), Tm(189-284), Tm(220-284(5OHW)), Tm(220-284), Tm(143-235), Tm(167-260), and Tm(143-260)) and one synthetic peptide (Ac-Tm(215-235)) to investigate the relative conformational stability of different regions derived from the C-terminal region of the protein, which is known to interact with the troponin complex. Analytical ultracentrifugation experiments show that the fragments that include the last 24 residues of the molecule (Tm(143-284(5OHW)), Tm(189-284(5OHW)), Tm(220-284(5OHW)), Tm(220-284)) are completely dimerized at 10 microm dimer (50 mm phosphate, 100 mm NaCl, 1.0 mm dithiothreitol, and 0.5 mm EDTA, 10 degrees C), whereas fragments that lack the native C terminus (Tm(143-235),Tm(167-260), and Tm(143-260)) are in a monomer-dimer equilibrium under these conditions. The presence of trifluoroethanol resulted in a reduction in the [theta](222)/[theta](208) circular dichroism ratio in all of the fragments and induced stable trimer formation only in those containing residues 261-284. Urea denaturation monitored by circular dichroism and fluorescence revealed that residues 261-284 of tropomyosin are very important for the stability of the C-terminal half of the molecule as a whole. Furthermore, the absence of this region greatly increases the cooperativity of urea-induced unfolding. Temperature and urea denaturation experiments show that Tm(143-235) is less stable than other fragments of the same size. We have identified a number of factors that may contribute to this particular instability, including an interhelix repulsion between g and e' positions of the heptad repeat, a charged residue at the hydrophobic coiled-coil interface, and a greater fraction of beta-branched residues located at d positions.     

The degenerative effect of a single intranigral injection of LPS on the dopaminergic system is prevented by dexamethasone,and not mimicked by rh-TNF-alpha,IL-1beta and IFN-gamma

It is becoming widely accepted that the inflammatory response is involved in neurodegenerative disease. In this context, we have developed an animal model of dopaminergic system degeneration by the intranigral injection of lipopolysaccharide (LPS), a potent inductor of inflammation. To address the importance of the inflammatory response in the LPS-induced degeneration of nigral dopaminergic neurones, we carried out two different kinds of studies: (i) the possible protective effect of an anti-inflammatory compound, and (ii) the effect of the intranigral injection of inflammatory cytokines (TNF-alpha, IL-1beta and IFN-gamma) on dopaminergic neurones viability. Present results show that dexamethasone, a potent anti-inflammatory drug that interferes with many of the features characterizing pro-inflammatory glial activation, prevented the loss of catecholamine content, Tyrosine hydroxylase (TH) activity and TH immunostaining induced by LPS-injection and also the bulk activation of microglia/macrophages. Surprisingly, injection of the pro-inflammatory cytokines failed to reproduce the LPS effect. Taken together, our results suggest that inflammatory response is implicated in LPS-induced neurodegeneration. This damage may be due, at least in part, to a cascade of events independent of that described for TNF-alpha/IL-1 beta/IFN-gamma.     

Cytometric,morphologic and enzymatic characterisation of haemocytes in Anodonta cygnea

The haemocytes in bivalve mussels are involved in many processes such as lesion repair, shell repair, elimination of small particles and toxic substances. In Anodonta cygnea there are two categories of haemolymph cells, the granulocytes and hyalinocytes. Two groups of cells were identified by flow cytometry and morphological studies: one with larger size and granularity representing 75%, and another group of cells (25%) which were approximately half the size. The cytochemical reactions showed peroxidase activity in the larger cells and a weak prophenoloxidase activity in the smaller cells. These characteristics suggest that the most common haemocytes are granulocytes and hyalinocytes are less common. Enzymatic studies showed clear activities of few enzymes in different compartments of the mantle. Both haemocytes presented significant variations for alpha-manosidase and beta-glucurosidase activities depending on the acid or alkaline pH. Almost all were sensitive to the pH changes, mainly the beta-galactosidase in the haemolymph plasma. On the contrary, the same enzymatic analysis in the extrapallial elements showed more stabilised activities. The simulation of acidic and alkaline condition with the observation of significant morphological and enzymatic activity changes, allow us to speculate some functional role, mainly in the haemolymph elements. The granulocytes may be speculated to have intense involvement in the digestion of small residues with the formation of calcareous stores while the hyalinocytes are more responsible for the elimination of soluble cytotoxic compounds.