Signal Transduction Pathways in Mycorrhizal Associations: Comparisons with the Rhizobium-Legume Symbiosis

A number of genera of soil fungi interact with plant roots to establish symbiotic associations whereby phosphate acquired by the fungus is exchanged for fixed carbon from the plant. Recent progress in investigating these associations, designated as mycorrhizae (sing., mycorrhiza), has led to the identification of specific steps in the establishment of the symbiosis in which the fungus and the plant interact in response to various molecular signals. Some of these signals are conserved with those of the Rhizobium-legume nitrogen-fixing symbiosis, suggesting that the two plant-microbe interactions share a common signal transduction pathway. Nevertheless, only legume hosts nodulate in response to Rhizobium, whereas the vast majority of flowering plants establish mycorrhizal associations. The key questions for the future are: what are the signal molecules produced by mycorrhizal fungi and how are they perceived by the plant? Copyright 1998 Academic Press.     

The role of mast cells and macrophages in amiodarone induced pulmonary fibrosis and the possible attenuating role of atorvastatin

Amiodarone (AM) is an effective anti-arrhythmic drug. We investigated the role of mast cells and macrophages on AM induced pulmonary fibrosis and the action of atorvastatin on this fibrosis. Rats were allocated into four groups; negative control (1), positive control (2), 30 mg/kg body weight/day AM (3) and AM + 10 mg/kg/day atorvastatin (4). Lungs were harvested and prepared for histology and immunohistochemistry. Hematoxylin and eosin stained sections of group 3 exhibited disorganized lung architecture. We found cellular debris in the lumen of both intrapulmonary bronchi and bronchioles with partial disruption of the thickened epithelial lining and mononuclear cellular infiltration into the lamina propria. We also observed thickening of the epithelial lining and the smooth muscle layer. Congested, dilated and thickened blood capillaries and thickened inter-alveolar septa were observed with mononuclear cellular infiltrates in the lung of group 3. Most alveoli were collapsed, but some dilated ones were detected. In some alveoli, type ?? pneumocytes were increased, while type I cells were decreased. We observed significant increases in the amount of collagen in the thickened inter-alveolar septa, around bronchioles and around blood capillaries in sections from group 3. We found a significant increase in mast cells and alveolar macrophages in group 3 compared to group 1. Mast cells and macrophages appear to play important roles in AM induced pulmonary fibrosis. Atorvastatin appears to attenuate this condition.     

Confirmation of quantitative trait loci affecting fatness in chickens

In this report we describe the analysis of an advanced intercross line (AIL) to confirm the quantitative trait locus (QTL) regions found for fatness traits in a previous study. QTL analysis was performed on chromosomes 1, 3, 4, 15, 18, and 27. The AIL was created by random intercrossing in each generation from generation 2 (G₂) onwards until generation 9 (G₉) was reached. QTL for abdominal fat weight (AFW) and/or percentage abdominal fat (AF%) on chromosomes 1, 3 and 27 were confirmed in the G₉ population. In addition, evidence for QTL for body weight at the age of 5 (BW5) and 7 (BW7) weeks and for the percentage of intramuscular fat (IF%) were found on chromosomes 1, 3, 15, and 27. Significant evidence for QTL was detected on chromosome 1 for BW5 and BW7. Suggestive evidence was found on chromosome 1 for AFW, AF% and IF%, on chromosome 15 for BW5, and on chromosome 27 for AF% and IF%. Furthermore, evidence on the chromosome-wise level was found on chromosome 3 for AFW, AF%, and BW7 and on chromosome 27 for BW5. For chromosomes 4 and 18, test statistics did not exceed the significance threshold.     

Genetic basis and functioning of the signal transduction system in plants under the conditions of viral resistance

This paper analyzes the genetic basis and modern conception of molecular mechanisms of recognition of pathogens, mainly viruses, by plants. The importance of signal systems and their key factors in plant organisms are discussed. The possible role of different elicitors in signal transduction processes is reviewed.     

RNA interference of proteasome subunit of PSMbeta7 gene restricts proteasome subunit PSMbeta1 and PSMbeta5 mRNA expression and peptidyl-glutamyl peptide-hydrolyzing proteasome activity in neonatal cardiomyocytes

Using small interfering RNA (siRNA) transfection of neonatal cardiomyocytes to inhibit expression of nonproteolytic proteasome beta7 subunit, we observed a significant decrease in beta1 proteolytic subunit mRNA expression. Proteasome peptidyl-glutamyl peptide-hydrolyzing activity decreased to 28% (0.48 +/- 0.2 nM AMC/min) compared to control (1.7 +/- 0.5 nM AMC/min) (P < 0.05). Beta5 Subunit mRNA expression decreased 21 times (P < 0.05) with no changes in its chymotrypsin-like activity. Proteasome trypsin-like activity and activity of another proteolytic enzyme tripeptidyl-peptidase II remained unchanged.     

Seroprevalence and risk factors of Q fever in goats on commercial dairy goat farms in the Netherlands, 2009-2010

Background

Highly pathogenic avian influenza (HPAI) viruses have had devastating effects on poultry industries worldwide, and there is concern about the potential for HPAI outbreaks in the poultry industry in Great Britain (GB). Critical to the potential for HPAI to spread between poultry premises are the connections made between farms by movements related to human activity. Movement records of catching teams and slaughterhouse vehicles were obtained from a large catching company, and these data were used in a simulation model of HPAI spread between farms serviced by the catching company, and surrounding (geographic) areas. The spread of HPAI through real-time movements was modelled, with the addition of spread via company personnel and local transmission.

Results

The model predicted that although large outbreaks are rare, they may occur, with long distances between infected premises. Final outbreak size was most sensitive to the probability of spread via slaughterhouse-linked movements whereas the probability of onward spread beyond an index premises was most sensitive to the frequency of company personnel movements.

Conclusions

Results obtained from this study show that, whilst there is the possibility that HPAI virus will jump from one cluster of farms to another, movements made by catching teams connected fewer poultry premises in an outbreak situation than slaughterhouses and company personnel. The potential connection of a large number of infected farms, however, highlights the importance of retaining up-to-date data on poultry premises so that control measures can be effectively prioritised in an outbreak situation.     

Azithromycin and cough-specific health status in patients with chronic obstructive pulmonary disease and chronic cough: a randomised controlled trial

Background

Macrolides reduce exacerbations in patients with COPD. Their effects on health status has not been assessed as primary outcome and is less clear. This study assessed the effects of prophylactic azithromycin on cough-specific health status in COPD-patients with chronic productive cough.

Methods

In this randomised controlled trial 84 patients met the eligibility criteria: age of ≥40 years, COPD GOLD stage ≥2 and chronic productive cough. The intervention-group (n = 42) received azithromycin 250 mg 3 times a week and the control-group (n = 42) received a placebo. Primary outcome was cough-specific health status at 12 weeks, measured with the Leicester Cough Questionnaire (LCQ). Secondary outcomes included generic and COPD-specific health status and exacerbations. Changes in adverse events and microbiology were monitored.

Results

Mean age of participants was 68 ± 10 years and mean FEV1 was 1.36 ± 0.47 L. The improvement in LCQ total score at 12 weeks was significantly greater with azithromycin (difference 1.3 ± 0.5, 95% CI 0.3;2.3, p = 0.01) and met the minimal clinically important difference. Similar results were found for the domain scores, and COPD-specific and generic health status questionnaires. Other secondary endpoints were non-significant. No imbalances in adverse events were found.

Conclusions

Prophylactic azithromycin improved cough-specific health status in COPD-patients with chronic productive cough to a clinically relevant degree.

Trial registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01071161","term_id":"NCT01071161"}}NCT01071161     

Pharmacological inhibition of GSK-3 in a guinea pig model of LPS-induced pulmonary inflammation: II. Effects on skeletal muscle atrophy

Background

Chronic obstructive pulmonary disease (COPD) is accompanied by pulmonary inflammation and associated with extra-pulmonary manifestations, including skeletal muscle atrophy. Glycogen synthase kinase-3 (GSK-3) has been implicated in the regulation of muscle protein- and myonuclear turnover; two crucial processes that determine muscle mass. In the present study we investigated the effect of the selective GSK-3 inhibitor SB216763 on muscle mass in a guinea pig model of lipopolysaccharide (LPS)-induced pulmonary inflammation-associated muscle atrophy.

Methods

Guinea pigs were pretreated with either intranasally instilled SB216763 or corresponding vehicle prior to each LPS/saline challenge twice weekly. Pulmonary inflammation was confirmed and indices of muscle mass were determined after 12 weeks. Additionally, cultured skeletal muscle cells were incubated with tumor necrosis factor α (TNF-α) or glucocorticoids (GCs) to model the systemic effects of pulmonary inflammation on myogenesis, in the presence or absence of GSK-3 inhibitors.

Results

Repeated LPS instillation induced muscle atrophy based on muscle weight and muscle fiber cross sectional area. Intriguingly, GSK-3 inhibition using SB216763 prevented the LPS-induced muscle mass decreases and myofiber atrophy. Indices of protein turnover signaling were unaltered in guinea pig muscle. Interestingly, inhibition of myogenesis of cultured muscle cells by TNF-α or synthetic GCs was prevented by GSK-3 inhibitors.

Conclusions

In a guinea pig model of LPS-induced pulmonary inflammation, GSK-3 inhibition prevents skeletal muscle atrophy without affecting pulmonary inflammation. Resistance to inflammation- or GC-induced impairment of myogenic differentiation, imposed by GSK-3 inhibition, suggests that sustained myogenesis may contribute to muscle mass maintenance despite persistent pulmonary inflammation. Collectively, these results warrant further exploration of GSK-3 as a potential novel drug target to prevent or reverse muscle wasting in COPD.     

Simultaneous determination of methocarbamol and aspirin by RP‐HPLC using fluorescence detection with time programming: its application to pharmaceutical dosage form

A new simple, rapid and sensitive reversed‐phase liquid chromatographic method was developed and validated for the simultaneous determination of methocarbamol (MET) and aspirin (ASP) in their combined dosage form. The separation of these compounds was achieved within 6.0 min on a CLC Shim‐pack C₈ column (250 × 4.6 mm, 5 µm particle size) using isocratic mobile phase consisting of acetonitrile and 0.02 M dihydrogenphosphate buffer (30:70, v/v) at pH = 5.0. The analysis was performed at a flow rate of 1.0 mL/min with fluorescence detection at 277/313 nm for MET and 298/410 nm for ASP using real‐time programming. The selectivity, linearity of calibration, accuracy, inter‐ and intra‐day precision and recovery were examined as parts of the method validation. The concentration–response relationship was linear over concentration ranges of 0.02‐0.20 and 0.02‐0.40 µg/mL for MET and ASP, respectively, with a limit of detection of 6 and 32 ng/mL for MET and ASP, respectively. The proposed method was successfully applied for the analysis of both MET and ASP in prepared tablets with average recoveries of 99.88 ± 0.65% for MET and 100.44 ± 0.78% for ASP. The results were favourably compared to those obtained by a reference method. Copyright © 2012 John Wiley & Sons, Ltd.