Origin of absorption changes associated with photoprotective energy dissipation in the absence of zeaxanthin.

To prevent photo-oxidative damage to the photosynthetic membrane in strong light, plants dissipate excess absorbed light energy as heat in a mechanism known as non-photochemical quenching (NPQ). NPQ is triggered by the trans-membrane proton gradient (ΔpH), which causes the protonation of the photosystem II light-harvesting antenna (LHCII) and the PsbS protein, as well as the de-epoxidation of the xanthophyll violaxanthin to zeaxanthin. The combination of these factors brings about formation of dissipative pigment interactions that quench the excess energy.

Potential protective role of IL15Rα during inflammation.

We have shown that TNFα specifically activates the interleukin-15 (IL15) system in cerebral endothelial cells composing the blood-brain barrier. To determine the functions of cerebral IL15 signaling in inflammation, we first treated mice with lipopolysaccharide (LPS) and determined the expression of the three receptor subtypes of IL15. Robust time-dependent upregulation occurred in all subunits.

Gastric metastases. An endoscopic series of ten cases.

We report a series of ten cases of the clinical, endoscopic and pathological features of gastric metastases. Patients were six women and four men between 54 and 88 years old, with gastric metastases from breast carcinoma (4), lung carcinoma (4) and melanoma (2). Patients underwent an upper gastrointestinal endoscopy for epigastralgia (2), hematemesis (2), dysphagia (1) and anemia (5).

Origin and quantification of circulating DNA in mice with human colorectal cancer xenografts.

Although circulating DNA (ctDNA) could be an attractive tool for early cancer detection, diagnosis, prognosis, monitoring or prediction of response to therapies, knowledge on its origin, form and rate of release is poor and often contradictory. Here, we describe an experimental system to systematically examine these aspects. Nude mice were xenografted with human HT29 or SW620 colorectal carcinoma (CRC) cells and ctDNA was analyzed by Q-PCR with highly specific and sensitive primer sets at different times post-graft.

Spectral dependence of energy transfer in wild-type peripheral light-harvesting complexes of photosynthetic bacteria.

The precise position of the upper exciton component and relevant vibronic transitions of the B850 ring in peripheral light-harvesting complexes from purple photosynthetic bacteria are important values for determining the exciton bandwidth and electronic structure of the B850 ring. To determine the presence of these components in wild-type LH2 complexes the pump-probe femtosecond transient spectra obtained with excitation into the 730-840 nm spectral range are analyzed. We show that at excitation wavelengths less than 780 nm B850 absorption bands are present and that, in accordance with exciton theory, these bands peak further in the blue when the lowest optically allowed transition is more red-shifted.

Pigment organization in fucoxanthin chlorophyll a/c(2) proteins (FCP) based on resonance Raman spectroscopy and sequence analysis.

Chlorophylls (Chls)-a and -c(2) are identified and characterized in fucoxanthin chlorophyll-a/c(2) protein (FCP) complexes in the trimeric (FCPa(trim)) and oligomeric (FCPb(olig)) forms of FCP from the diatom Cyclotella meneghiniana using resonance Raman (RR) spectroscopy. Importantly, two different Chl-c(2)s are identified in both FCPa(trim) and FCPb(olig) from their signature ring-breathing modes at approximately 1360 cm(-1). In addition, the C13(1)-keto carbonyl peaks indicate the presence of more than four Chl-a's in both FCP complexes and are broadly classified into three groups with strong, medium and weak external hydrogen bonds.

Electronic and protein structural dynamics of a photosensory histidine kinase.

The bacterium Caulobacter crescentus encodes a two-component signaling protein, LovK, that contains an N-terminal photosensory LOV domain coupled to a C-terminal histidine kinase. LovK binds a flavin cofactor, undergoes a reversible photocycle, and displays regulated ATPase and autophosphorylation activity in response to visible light. Femtosecond to nanosecond visible absorption spectroscopy demonstrates congruence between full-length LovK and isolated LOV domains in the mechanism and kinetics of light-dependent cysteinyl-C4(a) adduct formation and rupture, while steady-state absorption and fluorescence line narrowing (FLN) spectroscopies reveal unique features in the electronic structure of the LovK flavin cofactor.

The 2-Cys peroxiredoxin alkyl hydroperoxide reductase c binds heme and participates in its intracellular availability in Streptococcus agalactiae.

Heme is a redox-reactive molecule with vital and complex roles in bacterial metabolism, survival, and virulence. However, few intracellular heme partners were identified to date and are not well conserved in bacteria. The opportunistic pathogen Streptococcus agalactiae (group B Streptococcus) is a heme auxotroph, which acquires exogenous heme to activate an aerobic respiratory chain.

[Late complications from abdominal wall surgery: report of three cases of mesh migration into hollow viscus].

Laparoscopic mesh repair of ventral abdominal wall hernias is routinely performed. Mesh detachment and migration within the abdominal cavity is a late complication of this procedure. Symptoms are non-specific and imaging diagnosis is difficult to achieve because this complication is rare and overlooked.

Hepatic vascular flow measurements by phase contrast MRI and doppler echography: a comparative and reproducibility study.

Purpose: To directly compare and study the variability of parameters related to hepatic blood flow measurements using 3 T phase-contrast magnetic resonance imaging (PC-MRI) and Doppler ultrasound (US).

Materials And Methods: Nine healthy subjects were studied. Blood velocities and flow rate measurements were performed in the portal vein and the proper hepatic artery.

The disulfide bonds in glycoprotein E2 of hepatitis C virus reveal the tertiary organization of the molecule.

Hepatitis C virus (HCV), a major cause of chronic liver disease in humans, is the focus of intense research efforts worldwide. Yet structural data on the viral envelope glycoproteins E1 and E2 are scarce, in spite of their essential role in the viral life cycle. To obtain more information, we developed an efficient production system of recombinant E2 ectodomain (E2e), truncated immediately upstream its trans-membrane (TM) region, using Drosophila melanogaster cells.

Human recombinant anti-thyroperoxidase autoantibodies: in vitro cytotoxic activity on papillary thyroid cancer expressing TPO.

Background: Thyroid cancers are difficult to treat due to their limited responsiveness to chemo- and radiotherapy. There is thus a great interest in and a need for alternative therapeutic approaches.

Results: We studied the cytotoxic activity of anti-thyroperoxidase autoantibodies (anti-TPO aAbs, expressed in baculovirus/insect cell (B4) and CHO cells (B4') or purified from patients' sera) against a papillary thyroid cancer (NPA) cell line.

Structural and spectroscopic consequences of hexacoordination of a bacteriochlorophyll cofactor in the Rhodobacter sphaeroides reaction center .

The structural and functional consequences of changing the coordination state of one of the bacteriochlorophyll (BChl) cofactors in the purple bacterial reaction center have been explored. A combination of steady state spectroscopy and X-ray crystallography was used to demonstrate that mutagenesis of residue 181 of the L-polypeptide from Phe to Arg (FL181R) causes the BChl at the accessory (B(B)) position on the so-called inactive cofactor branch to become hexacoordinated, with no significant changes to the structure of the surrounding protein. This change was accompanied by the appearance of a distinctive absorbance band at 631 nm in the room-temperature absorbance spectrum.

Fluorescence line narrowing studies on isolated chlorophyll molecules.

Fluorescence line-narrowing and resonance Raman properties of various chlorophylls have been measured in organic solvents. Resonance Raman spectroscopy is already a well-established method for the study of photochemical reactions in the various pigment-protein complexes involved in photosynthesis, while fluorescence line-narrowing is still an emerging technique for such systems. Interpretation of these vibrational spectra requires accurate comparative data on the pure isolated pigments.

Measurement of long-range interatomic distances by solid-state tritium-NMR spectroscopy.

For the structural determination of a ligand bound to an amorphous macromolecular system, solid-state NMR can be used to provide interatomic distances. It is shown here that selective labeling in discrete locations with tritium enables accurate measurement of long-range distances owing to the high gyromagnetic ratio of this nucleus, without structural modification of the molecule. This approach gives access to the largest NMR distance ever measured between two nuclei (14.

Keystone Symposium on Antibodies as Drugs: March 27-April 1, 2009, Whistler, BC CA.

The symposium on Antibodies as Drugs, organized by Keystone Symposia and chaired by J. Marks, (University of California Los Angeles, USA), E.S.

[Embolization of recurrent bleeding jejunal varices].

We report a case of recurrent digestive haemorrhage due to bleeding ectopic jejunal varices complicating portal hypertension in a 51-year-old cirrhotic patient, treated 1 year ago by transjugular intrahepatic porto-systemic shunt (TIPS) for the same problem. Successful embolisation with coils, of ectopic varices, was performed using original transjugular and trans-TIPS route, without complication, and no recurrence during a follow-up of 24 months.

[Bispecific antibodies: what future?].

Monoclonal antibodies have emerged as a very successful class of therapeutic agents. In their native format, monoclonal antibodies are monospecific in that they recognize only one epitope, but their Fc domain also binds to FcfR-expressing cells. Attempts to improve the cytotoxicity of antibodies, particularly in the cancer field, have led to the design of bispecific antibodies: this can occur through various strategies, such as quadroma, thioether-linked Fab' gamma fragments or genetic engineering.

IL-15 receptor deletion results in circadian changes of locomotor and metabolic activity.

Interleukin-15 (IL-15) is a cytokine produced in the normal brain that acts on its specific receptor IL-15Ralpha and co-receptors IL-2Rbeta and IL-2Rgamma in neuronal cells. The functions of the cerebral IL-15 system, however, are not yet clear. To test the hypothesis that IL-15Ralpha regulates metabolic activity and body temperature, we quantified the specific metabolic phenotype of IL-15Ralpha knockout mice.

Combined cetuximab and trastuzumab are superior to gemcitabine in the treatment of human pancreatic carcinoma xenografts.

Background: Pancreatic carcinoma remains a treatment-refractory cancer with a poor prognosis. Here, we compared anti-epidermal growth factor receptor (EGFR) and anti-HER2 monoclonal antibodies (2mAbs) injections with standard gemcitabine treatment on human pancreatic carcinoma xenografts.

Materials And Methods: Nude mice, bearing human pancreatic carcinoma xenografts, were treated with either combined anti-EGFR (cetuximab) and anti-HER2 (trastuzumab) or gemcitabine, and tumor growth was observed.

[Bioproduction of pharmaceutical proteins: review and perspectives].

The increase in importance of the biopharmaceutical market generates enormous needs in production of therapeutic molecules. The world capacities of production, mainly therapeutic proteins, impossible to obtain by chemical synthesis, are at present insufficient. Besides the economic aspects in set, play, the question of the technologies used to produce these molecules is important: the tried(felt) technologies (bacteria, yeasts, cells of mammals), used for a long time rather widely remain expensive, or see their limited field of application; the innovative technologies (avian cells, animal and plant transgenic, among others), as for them, again have to show their ability.

Application of DENSE-MR-elastography to the human heart.

Typically, MR-elastography (MRE) encodes the propagation of monochromatic acoustic waves in the MR-phase images via sinusoidal gradients characterized by a detection frequency equal to the frequency of the mechanical vibration. Therefore, the echo time of a conventional MRE sequence is typically longer than the vibration period which is critical for heart tissue exhibiting a short T(2). Thus, fast acquisition techniques like the so-called fractional encoding of harmonic motions were developed for cardiac applications.

Carotenoid structures and environments in trimeric and oligomeric fucoxanthin chlorophyll a/c2 proteins from resonance Raman spectroscopy.

Resonance Raman (RR) spectroscopy is used to characterize the structures and environments of the carotenoid fucoxanthin (Fx), the primary light harvester in the membrane-intrinsic fucoxanthin chlorophyll a/c2 proteins(FCP) from the diatom Cyclotella meneghiniana, thereby building on the findings from Stark spectroscopy and calculations (J. Phys. Chem.