Large, rapidly evolving intergenic spacers in the mitochondrial DNA of the salamander family Ambystomatidae (Amphibia: Caudata)

We report the presence, in the mitochondrial DNA (mtDNA) of all of the sexual species of the salamander family Ambystomatidae, of a shared 240- bp intergenic spacer between tRNAThr and tRNAPro. We place the intergenic spacer in context by presenting the sequence of 1,746 bp of mtDNA from Ambystoma tigrinum tigrinum, describe the nucleotide composition of the intergenic spacer in all of the species of Ambystomatidae, and compare it to other coding and noncoding regions of Ambystoma and several other vertebrate mtDNAs. The nucleotide substitution rate of the intergenic spacer is approximately three times faster than the substitution rate of the control region, as shown by comparisons among six Ambystoma macrodactylum sequences and eight members of the Ambystoma tigrinum complex. We also found additional inserts within the intergenic spacers of five species that varied from 87-444 bp in length. The presence of the intergenic spacer in all sexual species of Ambystomatidae suggests that it arose at least 20 MYA and has been a stable component of the ambystomatid mtDNA ever since. As such, it represents one of the few examples of a large and persistent intergenic spacer in the mtDNA of any vertebrate clade.      

AN ELECTRON MICROSCOPE STUDY OF VITALLY STAINED SINGLE CELLS IRRADIATED WITH A RUBY LASER MICROBEAM

An electron microscope study has been made of vitally stained single cells whose cytoplasm has been subjected to a localized ruby laser microbeam. Light and moderate laser absorption (the resultant of stain concentration and laser energy density) produced restricted selective damage of mitochondria in cells stained with Janus green B; heavy laser absorption resulted in mitochondrial damage, as well as in nonselective interaction with other cell structures. With four other basic vital stains, the polysomes, ergastoplasm, mitochondria and other organelles at the irradiated site were uniformly damaged. Unstained cells showed no morphological alterations. With light primary damage (that restricted to the irradiation site), no secondary effects of the incident radiation were observed. With moderate primary damage, however, secondary damage of the mitochondria in the unirradiated cell portions was produced, which was reversible within 4 hr after irradiation. Heavy primary lesions caused severe secondary alteration of all cell structures that was irreversible and cell death occurred within 2 hr. Surviving cells examined 24 hr after light and moderate irradiation could not be distinguished from unirradiated controls. The possible mechanisms involved in the production of laser-induced cellular alterations are discussed.     

The sheathed flagellum of Brucella melitensis is involved in persistence in a murine model of infection

Persistence infection is the keystone of the ruminant and human diseases called brucellosis and Malta fever, respectively, and is linked to the intracellular tropism of Brucella spp. While described as non-motile, Brucella spp. have all the genes except the chemotactic system, necessary to assemble a functional flagellum. We undertook to determine whether these genes are expressed and are playing a role in some step of the disease process. We demonstrated that in the early log phase of a growth curve in 2YT nutrient broth, Brucella melitensis expresses genes corresponding to the basal (MS ring) and the distal (hook and filament) parts of the flagellar apparatus. Under these conditions, a polar and sheathed flagellar structure is visible by transmission electron microscopy (TEM). We evaluated the effect of mutations in flagellar genes of B. melitensis encoding various parts of the structure, MS ring, P ring, motor protein, secretion apparatus, hook and filament. None of these mutants gave a discernible phenotype as compared with the wild-type strain in cellular models of infection. In contrast, all these mutants were unable to establish a chronic infection in mice infected via the intraperitoneal route, raising the question of the biological role(s) of this flagellar appendage.     

GALNT11 as a new molecular marker in chronic lymphocytic leukemia

Aberrant mucin O-glycosylation often occurs in different cancers and is characterized by immature expression of simple mucin-type carbohydrates. At present, there are some controversial reports about the Tn antigen (GalNAcα-O-Ser/Thr) expression and there is a great lack of information about the [UDP-N-acetyl-α-d-galactosamine:polypeptide N-acetylgalactosaminyltransferase (GalNAc-Ts)] expression in chronic lymphocytic leukemia (CLL). To gain insight in these issues we evaluated the Tn antigen expression in CLL patient samples using two Tn binding proteins with different fine specificity. We also studied the expression from 14 GalNAc-Ts genes in CLL patients by RT-PCR. Our results have provided additional information about the expression level of the Tn antigen, suggesting that a low density of Tn residues is expressed in CLL cells. We also found that GALNT11 was expressed in CLL cells and normal T cell whereas little or no expression was found in normal B cells. Based on these results, GALNT11 expression was assessed by qPCR in a cohort of 50 CLL patients. We found significant over-expression of GALNT11 in 96% of B–CLL cells when compared to normal B cells. Moreover, we confirmed the expression of this enzyme at the protein level. Finally we found that GALNT11 expression was significantly associated with the mutational status of the immunoglobulin heavy chain variable region (IGHV), [?²(1) = 18.26; P < 0.0001], lipoprotein lipase expression [?²(1) = 13.72; P = 0.0002] and disease prognosis [?²(1) = 15.49; P < 0.0001]. Our evidence suggests that CLL patient samples harbor aberrant O-glycosylation highlighted by Tn antigen expression and that the over-expression of GALNT11 constitutes a new molecular marker for CLL.     

Exercise training in childhood-onset systemic lupus erythematosus: a controlled randomized trial

Introduction

Exercise training has emerged as a promising therapeutic strategy to counteract physical dysfunction in adult systemic lupus erythematosus. However, no longitudinal studies have evaluated the effects of an exercise training program in childhood-onset systemic lupus erythematosus (C-SLE) patients. The objective was to evaluate the safety and the efficacy of a supervised aerobic training program in improving the cardiorespiratory capacity in C-SLE patients.

Methods

Nineteen physically inactive C-SLE patients were randomly assigned into two groups: trained (TR, n = 10, supervised moderate-intensity aerobic exercise program) and non-trained (NT, n = 9). Gender-, body mass index (BMI)- and age-matched healthy children were recruited as controls (C, n = 10) for baseline (PRE) measurements only. C-SLE patients were assessed at PRE and after 12 weeks of training (POST). Main measurements included exercise tolerance and cardiorespiratory measurements in response to a maximal exercise (that is, peak VO₂, chronotropic reserve (CR), and the heart rate recovery (ΔHRR) (that is, the difference between HR at peak exercise and at both the first (ΔHRR1) and second (ΔHRR2) minutes of recovery after exercise).

Results

The C-SLE NT patients did not present changes in any of the cardiorespiratory parameters at POST (P > 0.05). In contrast, the exercise training program was effective in promoting significant increases in time-to-exhaustion (P = 0.01; ES = 1.07), peak speed (P = 0.01; ES = 1.08), peak VO₂ (P = 0.04; ES = 0.86), CR (P = 0.06; ES = 0.83), and in ΔHRR1 and ΔHRR2 (P = 0.003; ES = 1.29 and P = 0.0008; ES = 1.36, respectively) in the C-SLE TR when compared with the NT group. Moreover, cardiorespiratory parameters were comparable between C-SLE TR patients and C subjects after the exercise training intervention, as evidenced by the ANOVA analysis (P > 0.05, TR vs. C). SLEDAI-2K scores remained stable throughout the study.

Conclusion

A 3-month aerobic exercise training was safe and capable of ameliorating the cardiorespiratory capacity and the autonomic function in C-SLE patients.

Trial registration

NCT01515163.     

Potato tuber proteomics: comparison of two complementary extraction methods designed for 2-DE of acidic proteins

Two protein extraction procedures were tested in order to remove interfering compounds prior to 2-DE of potato tubers. These methods using SDS lysis buffer and phenol-phase extraction were compared regarding the quality of the resulting 2-D gel. While the resolution of SDS extracts on semipreparative gels seems better, both methods lead to similar extraction yields and total number of spots. The procedures are complementary regarding the Mr range of preferentially extracted proteins.     

Transient receptor potential, TRP channels: a new family of channels broadly expressed

Transient receptor potential, TRP channels are a new superfamily of functionally versatile non-selective cation channels present from yeast to mammals. On the basis of their structural homology, TRP channels are subdivided in 7 groups : TRPC 1-7 Canonical, TRPV 1-6 Vanilloid, TRPM 1-8 Melastatin, TRPP 1-3 Polycystin, TRPML Mucolipin, TRPA Ankyrin and TRPN (NO mechanotransducer potential C), the latter not expressed in mammals. Their cloning and heterologous expression allowed to demonstrating that these channels are generally weakly voltage-dependent. They are activated by various ligands involving a signal transduction cascade as well as directly by multiple compounds, heat and pH. TRP channels are found in a broad range of cell types. TRP channels are essential in allowing animals to sense the outside world and cells to sense their local environment. Following mutations or anomalous behaviour, these channels have a major role in several human diseases.     

Role of larval host plant experience and solanaceous plant volatile emissions in Tuta absoluta (Lepidoptera: Gelechiidae) host finding behavior

The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), is considered to be a major pest that damages tomato (Solanum lycopersicum L; Solanaceae) crops in South American, European, and Mediterranean countries. This insect species is polyphagous (i.e., feeds on many types of food); hence, it could also develop on other cultivated host plants, principally solanaceous plants, such as potato (S. tuberosum L.; Solanaceae) and eggplant (S. melongena L.; Solanaceae). Therefore, we tested the hypothesis that host plant choice by adult T. absoluta is influenced by plant volatile organic compounds and larval host plant experience. One tomato cultivar (cv.) ‘Moneymaker’ and three potato cv. ‘Charlotte’ ‘Bintje,’ and ‘Nicola’ were tested. Using a flying tunnel, we observed that females reared on tomato preferred flying toward tomato and, to a lesser extent, potato cv. ‘Charlotte.’ These preferences might be explained by the high release of terpenes by these two plants. When conducting oviposition choice assays, we found no preference between tomato and potato in the number of eggs laid by females that had been previously reared on either host plant. This study indicates that the host finding behavior of T. absoluta is mediated by solanaceous volatiles, while oviposition behavior appears to depend on additional stimuli. These results provide baseline information for use in the development of new control strategies against T. absoluta using semiochemicals and plant breeding.     

TNF-α is associated with loss of lean body mass only in already cachectic COPD patients

Background

Systemic inflammation may contribute to cachexia in patients with chronic obstructive pulmonary disease (COPD). In this longitudinal study we assessed the association between circulating C-reactive protein (CRP), tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6 levels and subsequent loss of fat free mass and fat mass in more than 400 COPD patients over three years.

Methods

The patients, aged 40–76, GOLD stage II-IV, were enrolled in 2006/07, and followed annually. Fat free mass and fat mass indexes (FFMI & FMI) were calculated using bioelectrical impedance, and CRP, TNF-α, IL-1ß, and IL-6 were measured using enzyme immunoassays. Associations with mean change in FFMI and FMI of the four inflammatory plasma markers, sex, age, smoking, FEV₁, inhaled steroids, arterial hypoxemia, and Charlson comorbidity score were analyzed with linear mixed models.

Results

At baseline, only CRP was significantly (but weakly) associated with FFMI (r = 0.18, p < 0.01) and FMI (r = 0.27, p < 0.01). Univariately, higher age, lower FEV₁, and use of beta2-agonists were the only significant predictors of decline in FFMI, whereas smoking, hypoxemia, Charlson score, and use of inhaled steroids predicted increased loss in FMI. Multivariately, high levels of TNF-α (but not CRP, IL-1ß or IL-6) significantly predicted loss of FFMI, however only in patients with established cachexia at entry.

Conclusion

This study does not support the hypothesis that systemic inflammation is the cause of accelerated loss of fat free mass in COPD patients, but suggests a role for TNF-α in already cachectic COPD patients.     

An efficient procedure for the production of fatty acid hydroperoxides from hydrolyzed flax seed oil and soybean lipoxygenase

Summary Production of 13-linolenic acid hydroperoxides from hydrolyzed flax seed oil using lipoxygenase extracted from soybean seeds.has been achieved with high transformation yields (60 g.l.^–1.h^–1) with a high purity (94 % of 13-isomers) in a 10 liter reactor without addition of any solvent or surfactant. The reaction limiting factor is, probably, the accessibility of the substrate to the enzyme.