Effect of maternal nitrogen and drought stress on seed dormancy and germinability of Amaranthus retroflexus

Amaranthus retroflexus L. is an importunate annual weed in many cropping systems of different countries. The main aim of this study was to investigate the effects of maternal nitrogen and drought stress on the seed dormancy and germinability of A. retroflexus. Field experiment was carried out in a factorial based on randomized complete block design, with four potential levels of soil water (–2, ?6, ?8 and ?10 bar) and three levels of nitrogen (0, 100 and 200 kg/ha). The germination characteristics of the seeds were measured at three different times (1 month, 6 months and 1 year after harvesting). Results showed that drought stress had positive effects on breaking of A. retroflexus seed dormancy until 6 months after seed harvesting. Seeds that were developed under severe water stress exhibited the highest germination percentage and germination rate. The results obtained from this study revealed that application of 100 kg/ha nitrogen during seed development increases germinability of A. retroflexus, whereas application of 200 kg/ha nitrogen induced seed dormancy. Furthermore, 100 kg/ha nitrogen application in the field along with 200 ppm gibberellic‐acid treatment during seed after‐ripening showed the highest germination percentage and germination rate for seeds after 6 months harvesting. Results also indicated that after‐ripening significantly increased seed germination and germination rate of A. retroflexus. These findings indicate that long‐term management of the soil seed bank in this species requires more stringent control due to the changes in germination timing, as detected in this study.     

The Novel Secreted Adipokine WNT1-inducible Signaling Pathway Protein 2 (WISP2) Is a Mesenchymal Cell Activator of Canonical WNT

WNT1-inducible-signaling pathway protein 2 (WISP2) is primarily expressed in mesenchymal stem cells, fibroblasts, and adipogenic precursor cells. It is both a secreted and cytosolic protein, the latter regulating precursor cell adipogenic commitment and PPARγ induction by BMP4. To examine the effect of the secreted protein, we expressed a full-length and a truncated, non-secreted WISP2 in NIH3T3 fibroblasts. Secreted, but not truncated WISP2 activated the canonical WNT pathway with increased β-catenin levels, its nuclear targeting phosphorylation, and LRP5/6 phosphorylation. It also inhibited Pparg activation and the effect of secreted WISP2 was reversed by the WNT antagonist DICKKOPF-1. Differentiated 3T3-L1 adipose cells were also target cells where extracellular WISP2 activated the canonical WNT pathway, inhibited Pparg and associated adipose genes and, similar to WNT3a, promoted partial dedifferentiation of the cells and the induction of a myofibroblast phenotype with activation of markers of fibrosis. Thus, WISP2 exerts dual actions in mesenchymal precursor cells; secreted WISP2 activates canonical WNT and maintains the cells in an undifferentiated state, whereas cytosolic WISP2 regulates adipogenic commitment.     

Radioprotective effects of hawthorn against genotoxicity induced by gamma irradiation in human blood lymphocytes

The radioprotective effect of hawthorn (Crataegus microphylla) fruit extract was investigated in cultured blood lymphocytes from human volunteers. Peripheral blood samples were collected from five human volunteers 10 min before and 1, 2 and 3 h after a single oral ingestion of 500 mg hawthorn powder extract. At each time point, the whole blood was exposed in vitro to 150 cGy of cobalt-60 gamma irradiation, and then the lymphocytes were cultured with mitogenic stimulation to determine the micronuclei in cytokinesis-blocked binucleated cell. The lymphocytes in the blood samples collected after extract ingestion exhibited a significant decrease in the incidence of binucleated cells containing micronuclei as compared to similarly irradiated lymphocytes collected prior to extract ingestion. The maximum decrease in the frequency of micronuclei-containing cells was observed at 1 h after ingestion of Hawthorn extract (on average a 44% decrease). These data suggest that it may be possible to use Hawthorn extracts in personnel exposed to radiation in order to protect lymphocytes from radiation effects.     

A Novel Probiotic Mixture Exerts a Therapeutic Effect on Experimental Autoimmune Encephalomyelitis Mediated by IL-10 Producing Regulatory T Cells

Background

Multiple sclerosis (MS) is a chronic inflammatory autoimmune disease of the central nervous system (CNS). One potential therapeutic strategy for MS is to induce regulatory cells that mediate immunological tolerance. Probiotics, including lactobacilli, are known to induce immunomodulatory activity with promising effects in inflammatory diseases. We tested the potential of various strains of lactobacilli for suppression of experimental autoimmune encephalomyelitis (EAE), an animal model of MS.

Methodology/Principal Findings

The preventive effects of five daily-administered strains of lactobacilli were investigated in mice developing EAE. After a primary screening, three Lactobacillus strains, L. paracasei DSM 13434, L. plantarum DSM 15312 and DSM 15313 that reduced inflammation in CNS and autoreactive T cell responses were chosen. L. paracasei and L. plantarum DSM 15312 induced CD4⁺CD25⁺Foxp3⁺ regulatory T cells (Tregs) in mesenteric lymph nodes (MLNs) and enhanced production of serum TGF-β1, while L. plantarum DSM 15313 increased serum IL-27 levels. Further screening of the chosen strains showed that each monostrain probiotic failed to be therapeutic in diseased mice, while a mixture of the three lactobacilli strains suppressed the progression and reversed the clinical and histological signs of EAE. The suppressive activity correlated with attenuation of pro-inflammatory Th1 and Th17 cytokines followed by IL-10 induction in MLNs, spleen and blood. Additional adoptive transfer studies demonstrated that IL-10 producing CD4⁺CD25⁺ Tregs are involved in the suppressive effect induced by the lactobacilli mixture.

Conclusions/Significance

Our data provide evidence showing that the therapeutic effect of the chosen mixture of probiotic lactobacilli was associated with induction of transferable tolerogenic Tregs in MLNs, but also in the periphery and the CNS, mediated through an IL-10-dependent mechanism. Our findings indicate a therapeutic potential of oral administration of a combination of probiotics and provide a more complete understanding of the host-commensal interactions that contribute to beneficial effects in autoimmune diseases.     

Cholestasis induced nephrotoxicity: The role of endogenous opioids

AimsElevated levels of endogenous opioids play a pivotal role in several deleterious consequences of cholestasis. Renal dysfunction occurs in cholestasis but its exact mechanism is still unknown. In this study, we investigated the role of endogenous opioids in cholestasis induced nephrotoxicity.Main methodsThirty-five rats were divided into five groups. In groups 1 and 2 BDL rats received either daily subcutaneous 20 mg/kg of naltrexone or its vehicle, for 7 days after BDL. In groups 3 and 4, BDL or Sham rats received no injections. In group 5, normal rats received subcutaneous injections of 20 mg/kg/day of naltrexone for 7 days. At the 7th day, 24 h urine was collected to measure urinary N-acetyl-β-D-glucosaminidase (NAG) as an early marker of renal tubular injury. Kidney samples were then collected for light and electron microscopic studies.Key findingsBDL significantly increased NAG activity compared to sham groups. Naltrexone significantly reversed NAG activity to normal levels in BDL animals. Naltrexone treatment in BDL animals also significantly reversed ALT and AST to their normal levels. In light and electron microscopic studies, there were significant structural alterations in BDL samples, which were mostly prevented in naltrexone treated BDL animals.SignificanceSignificant changes in urinary NAG activity and renal morphology of cholestatic rats were reversed by naltrexone treatment. These results suggest a possible role for endogenous opioids in inducing cholestatic nephrotoxicity.     

Cloning,high level expression and immunogenicity of 1163-1256 residues of C-terminal heavy chain of C. botulinum neurotoxin type E

Botulinum neurotoxins (BoNTs) inhibit neurotransmitter release from peripheral cholinergic synapses. BoNTs consist of a toxifying light chain and a heavy chain (HC) linked through a disulfide bond. In the present study we explored the immunogenicity and protective capability of the most effective part corresponding to 1163-1256 residues of botulinum type E neurotoxin HC gene. DNA encoding the 93 C-terminal amino acid of HC residues was synthesized with optimal codon usage for expression. These DNA fragments were ligated into a pLivSelect vector and subcloned into expression vector pET32a. Recombinant plasmids were then transformed into Escherichia coli strain BL21 DE3. The recombinant protein was purified by nickel affinity gel column chromatography. The HC1163-1256 was identified by antibodies raised against BoNT/E. HC1163-1256 was shown to bind with synaptotagmin and gangliosides, indicating that the expressed and purified HC1163-1256 protein retains a functionally active conformation. The immunization with recombinant protein induced a protection level in mice. The immunization with 2 μg of the recombinant protein induced a significant protection level in mice. In conclusion, availability of the recombinant protein provides an effective system to study the biochemical and physical interactions involved during BoNT binding to nerve cells and protection against its toxicity.     

Effects of epidural lidocaine analgesia on labor and delivery: A randomized, prospective, controlled trial

Background

Epidural anaesthesia is used extensively for cardiothoracic and vascular surgery in some centres, but not in others, with argument over the safety of the technique in patients who are usually extensively anticoagulated before, during, and after surgery. The principle concern is bleeding in the epidural space, leading to transient or persistent neurological problems.

Methods

We performed an extensive systematic review to find published cohorts of use of epidural catheters during vascular, cardiac, and thoracic surgery, using electronic searching, hand searching, and reference lists of retrieved articles.

Results

Twelve studies included 14,105 patients, of whom 5,026 (36%) had vascular surgery, 4,971 (35%) cardiac surgery, and 4,108 (29%) thoracic surgery. There were no cases of epidural haematoma, giving maximum risks following epidural anaesthesia in cardiac, thoracic, and vascular surgery of 1 in 1,700, 1 in 1,400 and 1 in 1,700 respectively. In all these surgery types combined the maximum expected rate would be 1 in 4,700. In all these patients combined there were eight cases of transient neurological injury, a rate of 1 in 1,700 (95% confidence interval 1 in 3,300 to 1 in 850). There were no cases of persistent neurological injury (maximum expected rate 1 in 4,600).

Conclusion

These estimates for cardiothoracic epidural anaesthesia should be the worst case. Limitations are inadequate denominators for different types of surgery in anticoagulated cardiothoracic or vascular patients more at risk of bleeding.     

Synthesis and antibacterial activity of new fluoroquinolones containing a substituted N-(phenethyl)piperazine moiety

N-(Phenethyl)piperazinyl quinolone derivatives that bear a methoxyimino-substituent have been synthesized and evaluated for antimicrobial activity against Gram-positive and Gram-negative microorganisms. In addition, to define structure-activity relationships, ciprofloxacin derivatives containing 2-oxo-2-phenylethyl or 2-hydroxyimino-2-phenylethyl moieties at N-4 position of piperazine ring were prepared and tested. Ciprofloxacin derivatives, containing a N-(chloro-substituted phenethyl) residue, showed in vitro Gram-positive and Gram-negative activity generally comparable or superior to that of reference quinolones.