Effect of endurance training on skeletal muscle myokine expression in obese men: identification of apelin as a novel myokine.

BACKGROUND: It has been suggested that the metabolic benefits of physical exercise could be mediated by myokines. We examined here the effect of exercise training on skeletal muscle expression of a panel of myokines in humans. Pathways regulating myokine expression were investigated in human myotubes. METHODS: Eleven obese non-diabetic male subjects were enrolled in an 8-week endurance training program. Insulin sensitivity was assessed by an oral glucose tolerance test. Subcutaneous adipose tissue and Vastus lateralis muscle biopsy samples were collected before and after training. RNAs were prepared from adipose tissue and skeletal muscle. Primary culture of myoblasts was established. RESULTS: As expected, exercise training improved aerobic capacity and decreased fat mass. No significant change in interleukin 6, fibroblast growth factor 21, myostatin (MSTN) or irisin mRNA level was found in muscle after training. A twofold increase in apelin mRNA level was found in muscle but not in adipose tissue. No change in circulating myokine and adipokine plasma levels was observed in the resting state in response to training. Interestingly, apelin was significantly expressed and secreted in primary human myotubes. Apelin gene expression was upregulated by cyclic AMP and calcium, unlike the other myokines investigated. Importantly, changes in muscle apelin mRNA levels were positively related to whole-body insulin sensitivity improvement. CONCLUSION: Collectively, our data show that exercise training upregulates muscle apelin expression in obese subjects. Apelin expression is induced by exercise signaling pathways and secreted in vitro in human primary myotubes, and may behave as a novel exercise-regulated myokine with autocrine/paracrine action.

Comment on "Topological insulators in ternary compounds with a honeycomb lattice".

A Comment on the Letter by Zhang et al., Phys. Rev. Lett. 106, 156402 (2011).

Probing time-dependent molecular dipoles on the attosecond time scale.

Photoinduced molecular processes start with the interaction of the instantaneous electric field of the incident light with the electronic degrees of freedom. This early attosecond electronic motion impacts the fate of the photoinduced reactions. We report the first observation of attosecond time scale electron dynamics in a series of small- and medium-sized neutral molecules (N(2), CO(2), and C(2)H(4)), monitoring time-dependent variations of the parent molecular ion yield in the ionization by an attosecond pulse, and thereby probing the time-dependent dipole induced by a moderately strong near-infrared laser field. This approach can be generalized to other molecular species and may be regarded as a first example of molecular attosecond Stark spectroscopy.

Adrenaline but not noradrenaline is a determinant of exercise-induced lipid mobilization in human subcutaneous adipose tissue.

The relative contribution of noradrenaline (norepinephrine) and adrenaline (epinephrine) in the control of lipid mobilization in subcutaneous adipose tissue (SCAT) during exercise was evaluated in men treated with a somatostatin analogue, octreotide. Eight lean and eight obese young men matched for age and physical fitness performed 60 min exercise bouts at 50% of their maximal oxygen consumption on two occasions: (1) during i.v. infusion of octreotide, and (2) during placebo infusion. Lipolysis and local blood flow changes in SCAT were evaluated using in situ microdialysis. Infusion of octreotide suppressed plasma insulin and growth hormone levels at rest and during exercise. It blocked the exercise-induced increase in plasma adrenaline while that of noradrenaline was unchanged. Plasma natriuretic peptides (NPs) level was higher at rest and during exercise under octreotide infusion in lean men. Under placebo, no difference was found in the exercise-induced increase in glycerol between the probe perfused with Ringer solution alone and that with phentolamine (an alpha-adrenergic receptor antagonist) in lean subjects while a greater increase in glycerol was observed in the obese subjects. Under placebo, propranolol infusion in the probe containing phentolamine reduced by about 45% exercise-induced glycerol release; this effect was fully suppressed under octreotide infusion while noradrenaline was still elevated and exercise-induced lipid mobilization maintained in both lean and obese individuals. In conclusion, blockade of beta-adrenergic receptors during exercise performed during infusion of octreotide (blocking the exercise-induced rise in adrenaline but not that of noradrenaline) does not alter the exercise-induced lipolysis. This suggests that adrenaline is the main adrenergic agent contributing to exercise-induced lipolysis in SCAT. Moreover, it is the combined action of insulin suppression and NPs release which explains the lipolytic response which remains under octreotide after full local blockade of fat cell adrenergic receptors. For the moment, it is unknown if results apply specifically to SCAT and exercise only or if conclusions could be extended to all forms of lipolysis in humans.

Predictors of talc slurry pleurodesis success in patients with malignant pleural effusions.

INTRODUCTION: Malignant pleural effusions are an important burden of malignant disease. Slurry talc pleurodesis remains one of the most common and effective therapeutic options. AIM: Investigate the predictive factors related with the efficacy of this technique in malignant pleural effusions. METHODS: Retrospective analysis of all pleurodesis performed during a 10-year period in a Pulmonology Unit. All demographic and clinical data were collected, including the histologic tumoral type and the biochemical, microbiological and cytological fluid features. Efficacy was defined as the lack of recurrence of pleural effusion. It was used Kaplan-Meyer analysis to estimate overall survival. RESULTS: From a total of 202 patients submitted to pleurodesis (47% men; mean age 66.9±12.02 years). Light's criteria identified 86.6% as exudates. We found 85.1% survival at 30-day post-pleurodesis, which means the therapy used has significant success. A logistic regression model applied explained that variance in post-pleurodesis events was mostly due to age and gender rather than pleural biochemical factors (X2(5)=44.648, p<0.001, R2 28.3%). CONCLUSION: This study suggests that clinical evaluation of biochemical values, bacteriological results and malignant tumor diagnosis may not be enough to predict post-pleurodesis relapse with high accuracy. Furthermore, we observed, in ten years of pleurodesis performed in our Hospital, that pleurodesis is an effective life prolonging therapy for patients that fit the criteria for this intervention.

Topological Crystalline Insulator in a New Bi Semiconducting Phase.

Topological crystalline insulators are a type of topological insulators whose topological surface states are protected by a crystal symmetry, thus the surface gap can be tuned by applying strain or an electric field. In this paper we predict by means of ab initio calculations a new phase of Bi which is a topological crystalline insulator characterized by a mirror Chern number nM = -2, but not a strong topological insulator. This system presents an exceptional property: at the (001) surface its Dirac cones are pinned at the surface high-symmetry points. As a consequence they are also protected by time-reversal symmetry and can survive against weak disorder even if in-plane mirror symmetry is broken at the surface. Taking advantage of this dual protection, we present a strategy to tune the band-gap based on a topological phase transition unique to this system. Since the spin-texture of these topological surface states reduces the back-scattering in carrier transport, this effective band-engineering is expected to be suitable for electronic and optoelectronic devices with reduced dissipation.

White-to-brite conversion in human adipocytes promotes metabolic reprogramming towards fatty acid anabolic and catabolic pathways.

OBJECTIVE: Fat depots with thermogenic activity have been identified in humans. In mice, the appearance of thermogenic adipocytes within white adipose depots (so-called brown-in-white i.e., brite or beige adipocytes) protects from obesity and insulin resistance. Brite adipocytes may originate from direct conversion of white adipocytes. The purpose of this work was to characterize the metabolism of human brite adipocytes. METHODS: Human multipotent adipose-derived stem cells were differentiated into white adipocytes and then treated with peroxisome proliferator-activated receptor (PPAR)γ or PPARα agonists between day 14 and day 18. Gene expression profiling was determined using DNA microarrays and RT-qPCR. Variations of mRNA levels were confirmed in differentiated human preadipocytes from primary cultures. Fatty acid and glucose metabolism was investigated using radiolabelled tracers, Western blot analyses and assessment of oxygen consumption. Pyruvate dehydrogenase kinase 4 (PDK4) knockdown was achieved using siRNA. In vivo, wild type and PPARα-null mice were treated with a ß3-adrenergic receptor agonist (CL316,243) to induce appearance of brite adipocytes in white fat depot. Determination of mRNA and protein levels was performed on inguinal white adipose tissue. RESULTS: PPAR agonists promote a conversion of white adipocytes into cells displaying a brite molecular pattern. This conversion is associated with transcriptional changes leading to major metabolic adaptations. Fatty acid anabolism i.e., fatty acid esterification into triglycerides, and catabolism i.e., lipolysis and fatty acid oxidation, are increased. Glucose utilization is redirected from oxidation towards glycerol-3-phophate production for triglyceride synthesis. This metabolic shift is dependent on the activation of PDK4 through inactivation of the pyruvate dehydrogenase complex. In vivo, PDK4 expression is markedly induced in wild-type mice in response to CL316,243, while this increase is blunted in PPARα-null mice displaying an impaired britening response. CONCLUSIONS: Conversion of human white fat cells into brite adipocytes results in a major metabolic reprogramming inducing fatty acid anabolic and catabolic pathways. PDK4 redirects glucose from oxidation towards triglyceride synthesis and favors the use of fatty acids as energy source for uncoupling mitochondria.

Truncated apolipoprotein E (ApoE) causes increased intracellular calcium and may mediate ApoE neurotoxicity.

Apolipoprotein E (apoE)-related synthetic peptides, the 22 kDa N-terminal thrombin-cleavage fragment of apoE (truncated apoE), and full-length apoE have all been shown to exhibit neurotoxic activity under certain culture conditions. In the present study, protease inhibitors reduced the neurotoxicity and proteolysis of full-length apoE but did not block the toxicity of truncated apoE or a synthetic apoE peptide, suggesting that fragments of apoE may account for its toxicity. Additional experiments demonstrated that both truncated apoE and the apoE peptide elicit an increase in intracellular calcium levels and subsequent death of embryonic rat hippocampal neurons in culture. Similar effects on calcium were found when the apoE peptide was applied to chick sympathetic neurons. The rise in intracellular calcium and the hippocampal cell death caused by the apoE peptide were significantly reduced by receptor-associated protein, removal of extracellular calcium, or administration of the specific NMDA glutamate receptor antagonist MK-801. These results suggest that apoE may be a source of both neurotoxicity and calcium influx that involves cell surface receptors. Such findings strengthen the hypothesis that apoE plays a direct role in the pathology of Alzheimer's disease.

Bacterial and host-derived cationic proteins bind alpha2-laminins and enhance Mycobacterium leprae attachment to human Schwann cells.

It has recently been demonstrated that laminin alpha2 chains present on the surface of Schwann cells are involved in the process of attachment of Mycobacterium leprae to these cells. In this study, a protein in the M. leprae cell wall that was found to be capable of binding alpha2-containing laminins (merosin) was isolated and characterized. The M. leprae laminin-binding protein was identified as a 21-kDa histone-like protein (Hlp), a highly conserved cationic protein present in other species of mycobacteria. The gene that encodes this protein was PCR amplified, cloned, and expressed, and the recombinant protein was shown to bind alpha2-laminins. More significantly, when added exogenously, Hlp was able to greatly enhance the attachment of mycobacteria to ST88-14 human Schwann cells. The capacity to bind alpha2-laminins and to enhance mycobacterial adherence to Schwann cells was also found in other cationic proteins such as host-derived histones. Moreover, mutation in the hlp gene was shown not to affect the capacity of mycobacteria to bind to ST88-14 cells, suggesting that alternative adhesins and/or pathways might be used by mycobacteria during the process of adherence to Schwann cells. The potential role of Hlp as a fortuitous virulence factor contributing to the pathogenesis of M. leprae-mediated nerve damage is discussed.

A thrombin cleavage fragment of apolipoprotein E exhibits isoform-specific neurotoxicity.

A 22 kDa fragment of apoE containing a putative cytotoxi domain was identified in postmortem human brain tissue and fresh CSF. This fragment is apparently equivalent to the major apoE thrombin cleavage product. In vitro toxicity assays demonstrate that the corresponding fragment derived from recombinantly expressed human apoE is toxic to primary neurons in culture and that the E4-derived fragment is significantly more toxic than the fragment derived from the E3 isoform. These results suggest that proteolytic fragments of apoE may play a direct role in the pathology associated with AD and other diseases in which apoE has been implicated.

Binding of alpha2-laminins by pathogenic and non-pathogenic mycobacteria and adherence to Schwann cells.

The ability of Mycobacterium leprae to specifically bind alpha2-laminins of Schwann cells has been described recently as being an important property of the leprosy bacillus, which could explain the neural tropism of M. leprae. Therefore, the extent of the expression of alpha2-laminin-binding properties among mycobacteria was investigated. In an ELISA-based assay, all three species of Mycobacterium tested (M. tuberculosis, M. chelonae and M. smegmatis) expressed laminin-binding capacity, suggesting that the ability to bind alpha2-laminins is conserved within the genus Mycobacterium. This report also demonstrated that not only M. leprae but all the mycobacterial species tested readily interacted with the ST88-14 cells, a human schwannoma cell line, and that the addition of soluble alpha2-laminins significantly increased their adherence to these cells. These results failed to demonstrate the presence in M. leprae of a unique system based on alpha2-laminins for adherence to Schwann cells.

Amyloid beta binding proteins in vitro and in normal human cerebrospinal fluid.

A major neuropathological feature of Alzheimer's disease (AD) is the deposition of amyloid beta (A beta) in the form of senile plaques. The A beta peptide exists both in a beta-pleated sheet fibrillar form in amyloid deposits and as a normal soluble protein in biological fluids. Numerous proteins have been identified immunohistochemically to be associated with senile plaques, where A beta is the major constituent. Some of the latter have also been suggested to be carriers of the normal soluble A beta (sA beta) including apolipoprotein J (apoJ), apolipoprotein E (apoE) and transthyretin (TTR). We have found, using several different methods, that numerous proteins can bind synthetic A beta peptides when high concentrations are used; however, using an affinity anti-sA beta column we confirm that apoJ is the major binding protein in pooled human cerebrospinal fluid. On the other hand it is known that apoE co-purifies with A beta biochemically extracted from senile plaques. In AD tissue there may be a change in the major apolipoprotein binding A beta from apoJ to apoE.

Effects of octreotide on experimental neurogenic orthostatic hypotension in anaesthetized dogs.

This paper investigates the effects of octreotide (0.1 mg/kg, subcutaneous) on cardiovascular adaptation during head-up tilt test in an experimental model of neurogenic orthostatic hypotension (OH) obtained by chronic sinoaortic denervation in anaesthetized dogs. Blood pressure (BP), heart rate (HR), spectral variability (Fast Fourier transformation on 512 consecutive points, delta t: 2 Hz) and plasma catecholamine levels were measured in a double blind cross-over randomized study versus placebo, in supine position and during a head-up tilt test (80 degrees, 10 min) in six sinoaortic denervated and six control (normal) dogs. In normal dogs, head-up tilt test significantly increased HR and diastolic blood pressure (DBP). Plasma noradrenaline levels and energy of the low frequency band (40-150 mHz) of systolic blood pressure (SBP) significantly increased whereas the energy of the low frequency band of HR significantly decreased. Placebo and octreotide failed to modify supine and head-up tilt values of the measured parameters (except the value of low frequency band of SBP, which increased after octreotide). In sinoaortic denervated dogs, supine values of BP, HR and plasma noradrenaline levels were significantly higher than in controls whereas the energy of the low frequency spectral band of HR and SBP was similar to controls. Head-up tilt test induced a dramatic decrease in BP. HR, plasma noradrenaline levels and energy of the low frequency band of SBP and HR remained unchanged during head-up tilt tests. Neither supine nor head-up tilt values of these parameters were modified 45 min after octreotide or placebo administration. These results show that sinoaortic denervation is a reproducible model of OH characterized by a lack of activation of sympathetic efferent pathways during head-up tilt tests. Octreotide at the dose used remains ineffective to prevent the fall in BP under these experimental conditions.

Further biochemical characterization of Mycobacterium leprae laminin-binding proteins.

It has been demonstrated that the alpha2 chain of laminin-2 present on the surface of Schwann cells is involved in the process of attachment of Mycobacterium leprae to these cells. Searching for M. leprae laminin-binding molecules, in a previous study we isolated and characterized the cationic proteins histone-like protein (Hlp) and ribosomal proteins S4 and S5 as potential adhesins involved in M. leprae-Schwann cell interaction. Hlp was shown to bind alpha2-laminins and to greatly enhance the attachment of mycobacteria to ST88-14 Schwann cells. In the present study, we investigated the laminin-binding capacity of the ribosomal proteins S4 and S5. The genes coding for these proteins were PCR amplified and their recombinant products were shown to bind alpha2-laminins in overlay assays. However, when tested in ELISA-based assays and in adhesion assays with ST88-14 cells, in contrast to Hlp, S4 and S5 failed to bind laminin and act as adhesins. The laminin-binding property and adhesin capacity of two basic host-derived proteins were also tested, and only histones, but not cytochrome c, were able to increase bacterial attachment to ST88-14 cells. Our data suggest that the alanine/lysine-rich sequences shared by Hlp and eukaryotic H1 histones might be involved in the binding of these cationic proteins to laminin.

Determination of beta2-agonists in bovine urine: comparison of two extraction/clean-up procedures for high-resolution gas chromatography-mass spectrometry analysis.

Two extraction/clean-up analytical procedures were investigated and compared regarding their recovery and matrix-purification efficiency for screening beta2-agonist residues in fortified bovine urine by high-resolution gas chromatography-mass spectrometry (GC-MS). The first procedure, based on an analytical method originally developed for detecting anabolic steroids, consists of the employment of the nonionic resin, Amberlite XAD-2, a styrene-divinylbenzene copolymer for solid-phase extraction (SPE), followed by liquid-liquid extraction with diethyl ether. The second focuses on the use of a mixed SPE cartridge (reversed-phase and ion-exchange sorbent, Bond Elut Certify). In both cases, the trimethylsilylated derivatives were analyzed by GC-MS with an ion-trap detector. Clenbuterol, salbutamol, and terbutaline were used to spike urine samples during the comparison experimental phase. Afterwards, tulobuterol, mabuterol, mapenterol, cimbuterol, and brombuterol were included in the evaluation of the second procedure (the Bond Elut Certify procedure). At this stage, the detection was accomplished by GC-MS (quadrupole mass analyzer) with selective ion monitoring acquisition. The isotopic dilution method with the hexadeuterated analogues of clenbuterol and salbutamol was applied to prepare calibration curves and calculate recovery percentages. With XAD-2 resin, terbutaline and salbutamol (resorcinol and phenol-type beta2-agonists, respectively) could not be detected at 20 ng/mL or at 40 ng/mL. In spite of clenbuterol having been detected at 20 ng/mL, the results obtained were not reproducible. The use of the reversed-phase and ion-exchange sorbent Bond Elut Certify allowed multiresidue detection and showed several advantages for the screening of clenbuterol such as higher recoveries, cleaner final extracts, reduced sample preparation time, less labor intensive, and easier solvent consumption and disposal. Recoveries over 88% (concentrations ranging from 0.5 to 10 ppb) and limits of detection equal to 0.5 ppb were met for all the beta2-agonists studied with the last method.

Development and validation of a screening method for DES, zeranol, and beta-zearalanol in bovine urine by HRGC-MS and evaluation of robustness for routine survey of the Brazilian herd.

A method and evaluated for screening and confirmation of diethylstilbestrol (DES), alpha- and beta-zearalanol in bovine urine was developed. The residues were extracted from urine by C18 cartridges and purified on alumina columns. For screening and confirmation purposes, the anabolic derivatives were analyzed by gas chromatography-mass spectrometry after derivatization with BSTFA + 1% TMCS or a solution of PFPA/acetone (1:2, v/v), respectively. The recovery of most analytes for the whole procedure was higher than 96%, with a detection limit of 0.5 ppb. This procedure is being routinely applied to the Brazilian National Program for the Control of Residues in Meat (PNCRBC).

[Effects of octreotide on experimental orthostatic neurogenic hypotension]. / Effets de l'octréotide sur l'hypotension orthostatique neurogène expérimentale.

The synthetic somatostatin analogue, octreotide, has recently been proposed for the treatment of both postprandial and orthostatic hypotension (OH) in humans with autonomic failure related to multiple system atrophy (MSA) or diabetes mellitus. However, pharmacodynamic data are not still available in experimental models of orthostatic hypotension. We investigated in a model of neurogenic orthostatic hypotension, obtained by chronic sinoaortic denervation (SAD) in chloralose-anaesthetized dogs, the effects of octreotide (0.1 mg/kg, subcutaneous route) during a double-blind cross-over study vs placebo. Blood pressure (BP) and heart rate (HR) average values, SBP and HR short-term variabilities (using fast Fourier transformation) in both low (LF: 50-150 mHz) and high frequency range (respiratory rate +/- 50 mHz) and plasma noradrenaline (NA) levels (HPLC) were measured in supine position and during head-up tilt test (HUT: 80 degrees, 10 min) before and 45 min after drug administration. In controls, as expected, head-up tilt test induced a significant increase in DBP (+14 +/- 8 mmHg), HR (+36 +/- 21 beat/min), NA (296 +/- 118 vs 141 +/- 63 pg/ml), SBP-LF (25 +/- 5 vs 14 +/- 3%) whereas HR-HF significantly decreased. The changes during head-up tilt test were not modified after placebo or octreotide administration. In SAD dogs, head-up tilt test elicited a dramatic fall in SBP (-74 +/- 39 mmHg), DBP (-20 +/- 15 mmHg) without any significant change in HR (-5 +/- 12 beat/min), NA (708 +/- 213 vs 606 +/- 331 pg/ml), SBP-LF (16 +/- 3 vs 16 +/- 3%), HR-HF (8 +/- 2 vs 7 +/- 1%). Octreotide or placebo failed to significantly modify any of the measured parameters during head-up tilt test performed 45 min after drug administration. At the dose used, octreotide elicited a 80% decrease in insulin plasma levels after 45 min in both normal and SAD dogs. These results suggest that 1) this experimental model of orthostatic hypotension in SAD dogs is reproductible and can be used to investigate the pharmacological effects of antihypotensive drugs, 2) cardiovascular and biochemical characteristics of the SAD model are similar to those observed in MSA and 3) octreotide, in these experimental conditions, is not able to correct the BP fall during head-up tilt test.

[Interferon alpha-2a treatment of 26 patients with chronic non-A non-B hepatitis. Predictive factors of response]. / Traitement par l'interféron alpha-2a de 26 cas d'hépatites chroniques non A-non B. Etude des facteurs prédictifs de réponse.

The type and predicting factors of response to alpha interferon therapy have been studied in 26 patients with chronic non-A non-B hepatitis. Interferon was administered three times weekly during 6 months at a dose of 3 millions units/day. Eleven patients (42 percent) had serum alanine aminotransferase levels below 1.5 times the upper limit of normal range at the end of treatment. Only eight (31 percent) patients had persistent normalization of seric alanine aminotransferase value, 6 months after the end of the interferon treatment. The main factors involved in the response to therapy were age, apparent duration of the disease, and mode of contamination: patients who responded to interferon were younger, had a shorter duration of hepatitis and a parenterally transmitted disease.

[Tomodensitometry and radioisotopic methods in the study of unilateral lung hyperlucencies of vascular origin]. / Tomodensitometria e métodos radioisotópicos no estudo das hipertransparências pulmonares unilaterais de causa vascular.

Among the causes of the radiological entity known as unilateral or total hyperlucent lung is the decreased blood flow in the lungs. Unilateral and total hyperlucent lung results, among other factors, from the decreased intrapulmonary blood flow. Classically, the diagnosis and haemodynamic evaluation of these situations were usually made through invasive methods: right heart catheterism to perform angiopneumography and pressure evaluations as well as oximetry at several levels of the vascular network, thoracic aortography eventually associated with selective arteriography to detect the abnormalities of the systemic thoracic circulation. In this context, the authors propose for the diagnosis and study of this pathology, a new non-invasive methodology. In order to achieve this propose, we studied 8 patients, all of them performed clinical and laboratory evaluations, chest chi-ray, electrocardiographic and functional respiratory exams, as well angiopneumography, thoracic aortography tomodensitometry including qualitative (to study the lung arterial vasculature) and quantitative (to evaluate CT density of each lung in Hounsefield unit and two radioisotopic tests, including a ventilation/perfusion study with 133 chi e and HAM-99mTc, through an original software--four parameter histograms allowing simultaneous information of ventilation and perfusion at the pixel level and estimation of the V/Q; the other is the pulmonary gating through which it is possible to identify and quantify the arterio-arterial shunts.(ABSTRACT TRUNCATED AT 250 WORDS)