Infectious agents in atherosclerotic cardiovascular diseases through oxidative stress

Accumulating evidence demonstrates that vascular oxidative stress is a critical feature of atherosclerotic process, potentially triggered by several infectious agents that are considered as risk co-factors for the atherosclerotic cardiovascular diseases (CVDs). C. pneumoniae has been shown to upregulate multiple enzymatic systems capable of producing reactive oxygen species (ROS) such as NADPH oxidase (NOX) and cyclooxygenase in vascular endothelial cells, NOX and cytochrome c oxidase in macrophages as well as nitric oxide synthase and lipoxygenase in platelets contributing to both early and late stages of atherosclerosis. P. gingivalis seems to be markedly involved in the atherosclerotic process as compared to A. actinomycetemcomitans contributing to LDL oxidation and foam cell formation. Particularly interesting is the evidence describing the NLRP3 inflammasome activation as a new molecular mechanism underlying P. gingivalis-induced oxidative stress and inflammation. Amongst viral agents, immunodeficiency virus-1 and hepatitis C virus seem to have a major role in promoting ROS production, contributing, hence, to the early stages of atherosclerosis including endothelial dysfunction and LDL oxidation. In conclusion, oxidative mechanisms activated by several infectious agents during the atherosclerotic process underlying CVDs are very complex and not well-known, remaining, thus, an attractive target for future research

New insights into Chlamydiae persistence: an energy metabolism strategy?

Chlamydiaceae is a family of obligate intracellular bacteria generally considered energy parasites. Several studies have suggested that Chlamydiae are capable of independently producing energy and, more importantly, several genes involved in the energy metabolism are up-regulated during the persistent state. Thus, it has been suggested that chlamydial persistence could be a complex and flexible metabolic strategy designed to favor a lengthy survival in the host cell by evading the immune response. In conclusion, more detailed studies on the shift in the chlamydial energy metabolism, from the active to the persistent form, may be helpful in future to determine whether chlamydial persistence observed in vitro does occur in vivo and whether chronic sequelae of chlamydial diseases may be related to the persistence

Obiettivi infermieristici nella gestione del catetere venoso centrale

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Complete Genome Sequence of a New Mastrevirus, Chickpea Redleaf Virus 2, from Australia

We present here the complete genome sequence of a novel mastrevirus isolated from Cicer arietinum (chickpea) from Australia. We propose the name chickpea redleaf virus 2

Development of a Novel Tissue Blot Hybridization Chain Reaction for the Identification of Plant Viruses

Assays for the high throughput screening of crops for virus monitoring need to be quick, easy, and low cost. One method involves using tissue blot immunoassays (TBIA), where plant stems are blotted onto nitrocellulose membrane and screened with available antibodies against a range of viruses. TBIAs are inexpensive but limited by antibody availability and specificity. To circumvent the antibody limitations, we developed the tissue blot hybridization chain reaction (TB-HCR). As with TBIA, plant stems are blotted onto a nitrocellulose membrane, however, TB-HCR involves using nucleic acid probes instead of antibodies. We demonstrated for the first time that TB-HCR can be used for plant viruses by designing and testing probes against species from several virus genera including begomovirus, polerovirus, luteovirus, cucumovirus, and alfamovirus. We also explored different hairpin reporter methods such as biotin/streptavidin-AP and the Alexa Fluor-488 Fluorophore. TB-HCR has applications for low-cost diagnostics for large sample numbers, rapid diagnostic deployment for new viruses, and can be performed as a preliminary triage assay prior to downstream applications

Fibrin glue improves osteochondral scaffold fixation: study on the human cadaveric knee exposed to continuous passive motion

SummaryObjectiveTo evaluate stability and integrity of bi-layer and three-layer collagen-hydroxyapatite (C-HA) osteochondral scaffolds in a human cadaveric knee exposed to continuous passive motion (CPM) with and without loading and the role of added fibrin glue to improve the press-fit fixation of C-HA scaffolds.DesignOsteochondral lesions (2.0 × 1.5 cm) were chiseled out on both condyles and trochlea in eight human cadaveric knees. A total of 24 bi-layer (5 mm, four in each condyle) or three-layer C-HA scaffolds (8 mm, eight in the trochlea, four in each condyle) were first press-fit implanted and underwent testing with CPM, 90 cycles, 0°–90°. The second set of 24 scaffolds was implanted in cleaned lesions with the addition of fibrin glue. Two knees with fibrin glue fixation were additionally exposed to 15 kg loading, with 30 cycles of CPM, 0°–30°. Then, the knees were reopened and the scaffolds were evaluated using semi-quantitative Drobnic and modified Bekkers scores.ResultsAll but two scaffolds remained in the lesions site throughout CPM. Two implants failed: both were bi-layer osteochondral scaffolds, press-fit implanted at the lateral femoral condyle (LFC). A statistically significant difference was obtained between press-fit and fibrin glue implants with both Drobnic (2.9 ± 0.7 vs 4.3 ± 0.1, P < 0.0005) and Bekkers (3.3 ± 1.0 vs 5.0 ± 0.1, P < 0.0005) scores. Additional knee loading did not affect fibrin glue scaffold fixation or integrity.ConclusionThis cadaveric study showed fibrin glue notably improved bi-layer or three-layer C-HA scaffold press-fit fixation regardless of lesion location. It is therefore recommended that fibrin glue be used during surgery to improve early post-operative C-HA scaffold stability and integrity

Genetic diversity and recombination between turnip yellows virus strains in Australia

Disease outbreaks caused by turnip yellows virus (TuYV), a member of the genus Polerovirus, family Luteoviridae, regularly occur in canola and pulse crops throughout Australia. To understand the genetic diversity of TuYV for resistance breeding and management, genome sequences of 28 TuYV isolates from different hosts and locations were determined using high-throughput sequencing (HTS). We aimed to identify the parts of the genome that were most variable and clarify the taxonomy of viruses related to TuYV. Poleroviruses contain seven open reading frames (ORFs): ORF 0–2, 3a, and 3–5. Phylogenetic analysis based on the genome sequences, including isolates of TuYV and brassica yellows virus (BrYV) from the GenBank database, showed that most genetic variation among isolates occurred in ORF 5, followed by ORF 0 and ORF 3a. Phylogenetic analysis of ORF 5 revealed three TuYV groups; P5 group 1 and group 3 shared 45–49% amino acid sequence identity, and group 2 is a recombinant between the other two. Phylogenomic analysis of the concatenated ORFs showed that TuYV is paraphyletic with respect to BrYV, and together these taxa form a well-supported monophyletic group. Our results support the hypothesis that TuYV and BrYV belong to the same species and that the phylogenetic topologies of ORF 0, 3a and 5 are incongruent and may not be informative for species demarcation. A number of beet western yellow virus (BWYV)- and TuYV-associated RNAs (aRNA) were also identified by HTS for the first time in Australia

Polyamine supplementation reduces DNA damage in adipose stem cells cultured in 3-D

According to previous research, natural polyamines exert a role in regulating cell committment and differentiation from stemness during skeletal development. In order to assess whether distinct polyamine patterns are associated with different skeletal cell types, primary cultures of stem cells, chondrocytes or osteoblasts were dedicated for HPLC analysis of intracellular polyamines. Spermine (SPM) and Spermidine (SPD) levels were higher in adipose derived stem cells (ASC) compared to mature skeletal cells, i.e. chondrocytes and osteoblasts, confirming the connection of polyamine content with stemness. To establish whether polyamines can protect ASC against oxidative DNA damage in a 3-D differentiation model, the level of gamma H2AX was measured by western blot, and found to correlate with age and BMI of patients. Addition of either polyamine to ASC was able to hinder DNA damage in the low micromolecular range, with marked reduction of gamma H2AX level at 10 mu M SPM and 5 mu M SPD. Molecular analysis of the mechanisms that might underlie the protective effect of polyamine supplementation evidences a possible involvement of autophagy. Altogether, these results support the idea that polyamines are able to manage both stem cell differentiation and cell oxidative damage, and therefore represent appealing tools for regenerative and cell based applications