Genetic variability in European <Emphasis Type="Italic">Leptestheria dahalacensis</Emphasis> (Rüppel, 1837) (Crustacea,Branchiopoda, Spinicaudata)

The genetic variability of the gonochoric Leptestheria dahalacensis (Rüppel, 1837) was studied through the analysis of mitochondrial and nuclear (microsatellite loci) markers in eight Italian and two Central European populations. Mitochondrial data exhibited a low variability, as only six mitotypes were scored: five in Italy and one for both Central European samples, with a very low number of substitutions. All analysed microsatellite loci were variable, with 3–5 alleles per locus and 1–4 alleles per population. All populations were at the Hardy–Weinberg equilibrium, with the exceptions of two samples for locus ldAC-16, due to heterozygote excess, and of four populations for locus ldAC-11, probably linked to the presence of null alleles. A substantial population structuring was found between Central European and Italian samples for both utilized markers. This observation may be explained by isolation by distance and/or recent isolation events. On the other hand, the absence of a clear inter-pond variability in Italian sample comparisons may be ascribed to high dispersal ability in the short range. Handling editor: K. Martens     

Lindane may modulate the female reproductive development through the interaction with ER-beta: an in vivo-in vitro approach

Lindane (gamma-HCH) is a persistent environmental pollutant that may act as endocrine disrupter, affecting the nervous, immune and reproductive system, possibly through endocrine-mediated mechanisms. Since both estrogen receptors (ER-alpha and -beta) have shown to be target for endocrine disruption, we investigated the role of gamma-HCH on the development of female reproductive system. For an in vivo evaluation of gamma-HCH effects during prenatal period, pregnant CD1 mice were treated p.o. on gestational days 9-16 with 15 mg/kg bw/day of gamma-HCH and vehicle. The in vivo findings in treated F1 pups - in the absence of signs of systemic toxicity - included increase in the absolute and relative and absolute uterus weight revealed on post-natal day 22, earlier vaginal patency and reduced diameters of primary oocytes at fully sexual maturity. No effects on steroid hormone metabolism (aromatase, testosterone catabolism) were observed. Thus, gamma-HCH elicited subtle effects on female reproductive development likely mediated by ER-beta-mediated pathway(s), without a concurrent impairment of steroid hormone metabolism. Furthermore, to verify whether the endocrine interference of gamma-HCH is attributable to stimulation of ER-beta-mediated pathway(s), its effect has been evaluated in vitro on a cell line, LNCaP, expressing only functional ER-beta. In vitro treatments revealed a concentration-related effect on LNCaP cell viability and proliferation. Significantly, the contemporary addition of a pure anti-estrogen, the ER antagonist ICI 182,780, completely reversed gamma-HCH effects indicating an ER-beta-mediated action. Our findings indicate that gamma-HCH may act as endocrine disruptor during the female reproductive system development and ER-beta as a potential target for this compound and other endocrine disrupting chemicals as well.     

Interactions Between Rhizoctonia Root Rot and the Foliar Common Bean Diseases Anthracnose and Rust

The effects of co‐inoculation of Rhizoctonia solani and Colletotrichum lindemuthianum or Uromyces appendiculatus at different inoculum levels were studied on the disease dynamics and on the growth of bean plants under greenhouse conditions. Bean seeds were sown in R. solani‐infested soil. Additional experiments in which seedlings were transplanted to infested soil were also carried out. Conidial suspensions of C. lindemuthianum or uredospores of U. appendiculatus were inoculated onto leaves at plant developmental stages V2 and V3, respectively. Interactions between root rot and the aerial diseases were observed depending on the inoculum levels and on the timing of R. solani inoculation. Anthracnose severity tended to be higher on R. solani‐infected plants. Conversely, R. solani infection significantly reduced diameter of pustules and rust severity. When seedlings were transplanted to soil infested with low levels of R. solani, root rot severity and density of R. solani in the soil were magnified at high levels of C. lindemuthianum or U. appendiculatus. In these experiments, a synergistic interaction between root rot and anthracnose was observed to affect the plant dry weight. Antagonistic effects on the plant dry weight were found for the combination root rot/rust only when seeds were sown in infested soil.     

Molecular taxonomy and phylogenetic relationships among Australian Nasutitermes and Tumulitermes genera (Isoptera, Nasutitermitinae) inferred from mitochondrial COII and 16S sequences

The subfamily Nasutitermitinae Hare (1937) is a tropical and subtropical group, generally considered as the most specialised subfamily of Termitidae. To highlight some taxonomic inconsistencies, the phylogenetic relationships among seven Australian species, morphologically ascribed to the genera Nasutitermes and Tumulitermes, were studied through the analyses of the mitochondrial markers cytochrome oxidase II and 16S ribosomal RNA genes. In our trees, N. longipennis samples clearly pertain to two different specific entities with an apparently parapatric distribution. Further, the phylogenetic analysis performed on separated and combined data sets shows the placement of Tumulitermes species within a clade grouping Nasutitermes ones, and vice versa. Tests for alternative topologies do not support the monophyly of the genera Nasutitermes and Tumulitermes. Our results confirm the hypothesis that the morphological features used to establish relationships among these species are not phylogenetically decisive.     

Macrophage receptors implicated in the “adaptive” form of innate immunity

The adaptive component of innate immunity occurs during the course of infection when antigen presenting cells alter expression of soluble or surface associated pattern recognition receptors. This results in increased recognition of a broad spectrum of pathogens, enhancement of effector functions and altered regulation of the inflammatory response.     

Macrophage receptors implicated in the "adaptive" form of innate immunity

The adaptive component of innate immunity occurs during the course of infection when antigen presenting cells alter expression of soluble or surface associated pattern recognition receptors. This results in increased recognition of a broad spectrum of pathogens, enhancement of effector functions and altered regulation of the inflammatory response.     

Bacteriocins from lactic acid bacteria and their potential in the preservation of fruit products

Bacteriocins produced by lactic acid bacteria (LAB) are well-recognized for their potential as natural food preservatives. These antimicrobial peptides usually do not change the sensorial properties of food products and can be used in combination with traditional preservation methods to ensure microbial stability. In recent years, fruit products are increasingly being associated with food-borne pathogens and spoilage microorganisms, and bacteriocins are important candidates to preserve these products. Bacteriocins have been extensively studied to preserve foods of animal origin. However, little information is available for their use in vegetable products, especially in minimally processed ready-to-eat fruits. Although, many bacteriocins possess useful characteristics that can be used to preserve fruit products, to date, only nisin, enterocin AS-48, bovicin HC5, enterocin 416K1, pediocin and bificin C6165 have been tested for their activity against spoilage and pathogenic microorganisms in these products. Among these, only nisin and pediocin are approved to be commercially used as food additives, and their use in fruit products is still limited to certain countries. Considering the increasing demand for fresh-tasting fruit products and concern for public safety, the study of other bacteriocins with biochemical characteristics that make them candidates for the preservation of these products are of great interest. Efforts for their approval as food additives are also important. In this review, we discuss why the study of bacteriocins as an alternative method to preserve fruit products is important; we detail the biotechnological approaches for the use of bacteriocins in fruit products; and describe some bacteriocins that have been tested and have potential to be tested for the preservation of fruit products.     

Structural characterization of PTX3 disulfide bond network and its multimeric status in cumulus matrix organization

PTX3 is an acute phase glycoprotein that plays key roles in resistance to certain pathogens and in female fertility. PTX3 exerts its functions by interacting with a number of structurally unrelated molecules, a capacity that is likely to rely on its complex multimeric structure stabilized by interchain disulfide bonds. In this study, PAGE analyses performed under both native and denaturing conditions indicated that human recombinant PTX3 is mainly composed of covalently linked octamers. The network of disulfide bonds supporting this octameric assembly was resolved by mass spectrometry and Cys to Ser site-directed mutagenesis. Here we report that cysteine residues at positions 47, 49, and 103 in the N-terminal domain form three symmetric interchain disulfide bonds stabilizing four protein subunits in a tetrameric arrangement. Additional interchain disulfide bonds formed by the C-terminal domain cysteines Cys(317) and Cys(318) are responsible for linking the PTX3 tetramers into octamers. We also identified three intrachain disulfide bonds within the C-terminal domain that we used as structural constraints to build a new three-dimensional model for this domain. Previously it has been shown that PTX3 is a key component of the cumulus oophorus extracellular matrix, which forms around the oocyte prior to ovulation, because cumuli from PTX3(-/-) mice show defective matrix organization. Recombinant PTX3 is able to restore the normal phenotype ex vivo in cumuli from PTX3(-/-) mice. Here we demonstrate that PTX3 Cys to Ser mutants, mainly assembled into tetramers, exhibited wild type rescue activity, whereas a mutant, predominantly composed of dimers, had impaired functionality. These findings indicate that protein oligomerization is essential for PTX3 activity within the cumulus matrix and implicate PTX3 tetramers as the functional molecular units required for cumulus matrix organization and stabilization.     

Ethanol production from cheese whey permeate by Kluyveromyces marxianus UFV-3: A flux analysis of oxido-reductive metabolism as a function of lactose concentration and oxygen levels

In order to investigate the effect of lactose concentration and oxygen level on the growth and metabolism of Kluyveromyces marxianus UFV-3 in cheese whey permeate, batch cultures were conducted under aerobic, hypoxic, and anoxic conditions, with lactose at initial concentration ranging from 1 to 240 g L⁻¹. The increase in lactose concentration increased ethanol yield and ethanol volumetric productivity, and has reduced cell yield. When lactose concentration was equal or above 50 g L⁻¹ and the oxygen levels were low, the ethanol yield was close to its theoretical value. Maximum ethanol concentrations attained in this study were 76 and 80 g L⁻¹ in hipoxia and anoxia, respectively. The lactose consumption rate in anoxia was greater than in aerobiosis and hipoxia. However, under anoxia, the lactose consumption rate of K. marxianus followed a saturation kinetics, which was not observed in hypoxia and aerobiosis. All oxygen levels investigated, showed a tendency for saturation of the ethanol production rate above 65 g L⁻¹ lactose. Ethanol production rate was also higher on anoxia.     

Bacterial lipopolysaccharide activates nuclear factor-kappaB through interleukin-1 signaling mediators in cultured human dermal endothelial cells and mononuclear phagocytes

Bacterial lipopolysaccharide (LPS)-mediated immune responses, including activation of monocytes, macrophages, and endothelial cells, play an important role in the pathogenesis of Gram-negative bacteria-induced sepsis syndrome. Activation of NF-kappaB is thought to be required for cytokine release from LPS-responsive cells, a critical step for endotoxic effects. Here we investigated the role and involvement of interleukin-1 (IL-1) and tumor necrosis factor (TNF-alpha) signal transducer molecules in LPS signaling in human dermal microvessel endothelial cells (HDMEC) and THP-1 monocytic cells. LPS stimulation of HDMEC and THP-1 cells initiated an IL-1 receptor-like NF-kappaB signaling cascade. In transient cotransfection experiments, dominant negative mutants of the IL-1 signaling pathway, including MyD88, IRAK, IRAK2, and TRAF6 inhibited both IL-1- and LPS-induced NF-kappaB-luciferase activity. LPS-induced NF-kappaB activation was not inhibited by a dominant negative mutant of TRAF2 that is involved in TNF signaling. LPS-induced activation of NF-kappaB-responsive reporter gene was not inhibited by IL-1 receptor antagonist. TLR2 and TLR4 were expressed on the cell surface of HDMEC and THP-1 cells. These findings suggest that a signal transduction molecule in the LPS receptor complex may belong to the IL-1 receptor/toll-like receptor (TLR) super family, and the LPS signaling cascade uses an analogous molecular framework for signaling as IL-1 in mononuclear phagocytes and endothelial cells.