Sperm DNA fragmentation and oxidation are independent of malondialdheyde

Background  

There is clinical evidence to show that sperm DNA damage could be a marker of sperm quality and extensive data exist on the relationship between DNA damage and male fertility status. Detecting such damage in sperm could provide new elements besides semen parameters in diagnosing male infertility. We aimed to assess sperm DNA fragmentation and oxidation and to study the association between these two markers, routine semen parameters and malondialdehyde formation.     

The role of the Notch pathway in healthy and osteoarthritic articular cartilage: from experimental models to <Emphasis Type="Italic">ex vivo</Emphasis> studies

Osteoarthritis is the most prevalent form of arthritis in the world. With the progressive ageing of the population, it is becoming a major public health problem. The involvement of certain signaling pathways, such as the Notch pathway, during cartilage pathology has been reported. In this review, we report on studies that investigated the expression pattern of the Notch family members in articular cartilage and the eventual involvement of this pathway in the modulation of the physiology and pathology of chondrocytes. Temporal and/or spatial modulation of this signaling pathway may help these cells to synthesize a new functional extracellular matrix and restore the functional properties of the articular cartilage.     

P2X4 Assembles with P2X7 and Pannexin-1 in Gingival Epithelial Cells and Modulates ATP-induced Reactive Oxygen Species Production and Inflammasome Activation

We have previously reported that Porphyromonas gingivalis infection of gingival epithelial cells (GEC) requires an exogenous danger signal such as ATP to activate an inflammasome and caspase-1, thereby inducing secretion of interleukin (IL)-1β. Stimulation with extracellular ATP also stimulates production of reactive oxygen species (ROS) in GEC. However, the mechanism by which ROS is generated in response to ATP, and the role that different purinergic receptors may play in inflammasome activation, is still unclear. In this study, we revealed that the purinergic receptor P2X₄ is assembled with the receptor P2X₇ and its associated pore, pannexin-1. ATP induces ROS production through a complex consisting of the P2X₄, P2X_7, and pannexin-1. P2X₇−mediated ROS production can activate the NLRP3 inflammasome and caspase-1. Furthermore, separate depletion or inhibition of P2X₄, P2X₇, or pannexin-1 complex blocks IL-1β secretion in P. gingivalis-infected GEC following ATP treatment. However, activation via P2X₄ alone induces ROS generation but not inflammasome activation. These results suggest that ROS is generated through stimulation of a P2X₄/P2X₇/pannexin-1 complex, and reveal an unexpected role for P2X₄, which acts as a positive regulator of inflammasome activation during microbial infection.     

Mass spectrometry imaging is moving toward drug protein co-localization

Mass spectrometry (MS)-based technology provides label-free localization of molecules in tissue samples. Drugs, proteins, lipids and metabolites can easily be monitored in their environment. Resolution can be achieved down to the cellular level (10-20μm) for conventional matrix-assisted laser desorption/ionization (MALDI) imaging, or even to the subcellular level for more complex technologies such as secondary ionization mass spectrometry (SIMS) imaging. One question remains: are we going to be able to investigate functional relationships between drugs and proteins and compare with localized phenomena? This review describes the various spatial levels of investigation offered by mass spectrometry imaging (MSI), and the advantages and disadvantages compared with other labeling technologies.     

Enzymatic transesterification of palm stearin and olein blends to produce zero-trans margarine fat

ABSTRACT: BACKGROUND: Food industries aim to replace trans fat in their products by formulations having equivalent functionality and economic viability. Enzymatic transesterification can be a technological option to produce trans free fats targeting commercial applications. RESULTS: Palm stearin and palm olein blends in different ratios were enzymatically transesterified in a solvent free system using a Rhizopus oryzae lipase immobilised onto CaCO3 to produce a suitable fat for margarine formulation. Slip melting points and triacylglycerols profiles were evaluated upon transesterification. Results indicated that all transesterified blends had lower slip melting points than their non transesterified counterparts. Furthermore, the triacylglycerols profile showed a decrease in the concentration of the high melting point triacylglycerols. The rheological analysis showed that margarine prepared with the transesterified blend showed a better spreadability than that of a control margarine prepared with non transesterified fat. Adding powder of dry bark orange to margarine preparation improved its colour and fairly affected its spreadability and rheological behaviour. The margarine prepared with transesterified fat displayed a rheological behaviour that was comparable to that of commercial sample. CONCLUSIONS: This study is an ecofriendly approach to the utilization of relatively low value bioresources like palm stearin and palm olein for making margarine free of trans fatty acids that are now implicated as risk factor for heart diseases.     

Abundance and biomass of rotifers in relation to the environmental factors in geothermal waters in Southern Tunisia

The spatial and temporal dynamics of rotifers in relation to the physico-chemical parameters in Fish-Culture Research Station (Southern Tunisia) were studied monthly from February 2005 to January 2006. Thirteen rotifer species were found: Brachionus urceolaris, Brachionus calyciflorus, Brachionus sp., Lecane stichaea, Lecane rhytida, Lecane sp., Hexarthra mira, Rotaria tardigrada, Conochiloides natans, Trichocerca marina, Keratella quadrata, Keratella cochlearis and Notommata codonella. The most dominant rotifer was B. urceolaris (76% of total abundance). Rotifer density and water temperature were negatively correlated (r=−0.94, n=12, p=0.001). The highest abundance of rotifers was found in basin 4 (1.5×10⁵ ind m⁻³, in June 2005).     

<Emphasis Type="Italic">Prays oleae</Emphasis> Midgut Putative Receptor of <Emphasis Type="Italic">Bacillus thuringiensis</Emphasis> Vegetative Insecticidal Protein Vip3LB Differs from that of Cry1Ac Toxin

Vegetative insecticidal protein (Vip) is a class of insecticidal proteins produced by many Bacillus thuringiensis strains during their vegetative growth stage. The vip3LB gene of B. thuringiensis strain BUPM95, which encodes a protein active against the Lepidoptera olive tree pathogenic insect Prays oleae, was cloned into pET-14b vector and overexpressed in Escherichia coli. The expressed Vip3LB protein, found in the E. coli cytoplasmic fraction, was purified and used to produce anti-Vip3LB antibodies. Using the midgut extract of P. oleae, the purified Vip3LB bound to a 65-kDa protein, whereas Cry1Ac toxin bound to a 210-kDa midgut putative receptor. This result justifies the importance of the biological pest control agent Vip3LB that could be used as another alternative particularly in case of resistance to Cry toxins.     

A case of hemoglobin D Punjab in Tunisia. Characterization and structural study

Hb D Punjab is a hemoglobin abnormality due to the substitution of a glutamic acid by a glutamic on the hemoglobin beta chain: beta 121 Glu----Gln. Authors report here the first case of this rare variant in a tunisian family.     

Heterologous expression and periplasmic secretion of an antifungal Bacillus amyloliquefaciensBLB369 endo‐β‐1,3‐1,4‐glucanase in Escherichia coli

The endo‐β‐1,3‐1,4‐glucanases are glycoside hydrolases involved in the enzymatic depolymerization of 1,3‐1,4 β‐glucans and showed an antifungal activity against some fungi. Bacillus amyloliquefaciensBLB369 has a high antagonistic activity against phytopathogenic fungi. Its glu369 full‐coding sequence of the endo‐β‐1,3‐1,4‐glucanase gene (732 bp) was sequenced, cloned and successfully expressed in Escherichia coli Top10. The encoded protein (243 amino acids) has a calculated molecular mass of 27.3 kDa. To simplify the purification procedure, the glu369 coding sequence was cloned into the vector pKJD4. The produced OmpA‐His‐Glu369 harboured OmpA signal sequence for E. coli periplasmic localization and followed by a 6His residues for its purification. The purified His‐tagged proteins revealed two bands on SDS‐PAGE analysis with molecular masses of about 30.5 (His‐Glu369) and 32.5 kDa (OmpA‐His‐Glu369). They had the ability to inhibit the growth of phytopathogenic fungus Alternaria alternata. These favourable properties make the endo‐β‐1,3‐1,4‐glucanase a good candidate for biotechnological applications.