Mirror symmetry breaking through an internal degree of freedom leading to directional motion

We analyze here the minimal conditions for directional motion (net flow in phase space) of a molecular motor placed on a mirror-symmetric environment and driven by a center-symmetric and time-periodic force field. The complete characterization of the deterministic limit of the dissipative dynamics of several realizations of this minimal model, reveals a complex structure in the phase diagram in parameter space, with intertwined regions of pinning (closed orbits) and directional motion. This demonstrates that the mirror-symmetry breaking which is needed for directional motion to occur, can operate through an internal degree of freedom coupled to the translational one.Comment: Accepted for publication in Phys. Rev.

Green tea halts progression of cardiac transthyretin amyloidosis: an observational report

BACKGROUND: Treatment options in patients with amyloidotic transthyretin (ATTR) cardiomyopathy are limited. Epigallocatechin-3-gallate (EGCG), the most abundant catechin in green tea (GT), inhibits fibril formation from several amyloidogenic proteins in vitro. Thus, it might also halt progression of TTR amyloidosis. This is a single-center observational report on the effects of GT consumption in patients with ATTR cardiomopathy. METHODS: 19 patients with ATTR cardiomyopathy were evaluated by standard blood tests, echocardiography, and cardiac MRI (n = 9) before and after consumption of GT and/or green tea extracts (GTE) for 12 months. RESULTS: Five patients were not followed up for reasons of death (n = 2), discontinuation of GT/GTE consumption (n = 2), and heart transplantation (n = 1). After 12 months no increase of left ventricular (LV) wall thickness and LV myocardial mass was observed by echocardiography. In the subgroup of patients evaluated by cardiac MRI a mean decrease of LV myocardial mass (-12.5 %) was detected in all patients. This was accompanied by an increase of mean mitral annular systolic velocity of 9 % in all 14 patients. Total cholesterol (191.9 ± 8.9 vs. 172.7 ± 9.4 mg/dL; p < 0.01) and LDL cholesterol (105.8 ± 7.6 vs. 89.5 ± 8.0 mg/dL; p < 0.01) decreased significantly during the observational period. No serious adverse effects were reported by any of the participants. CONCLUSIONS: Our observation suggests an inhibitory effect of GT and/or GTE on the progression of cardiac amyloidosis. We propose a randomized placebo-controlled investigation to confirm our observation

Generalized quantum Fokker-Planck, diffusion and Smoluchowski equations with true probability distribution functions

Traditionally, the quantum Brownian motion is described by Fokker-Planck or diffusion equations in terms of quasi-probability distribution functions, e.g., Wigner functions. These often become singular or negative in the full quantum regime. In this paper a simple approach to non-Markovian theory of quantum Brownian motion using {\it true probability distribution functions} is presented. Based on an initial coherent state representation of the bath oscillators and an equilibrium canonical distribution of the quantum mechanical mean values of their co-ordinates and momenta we derive a generalized quantum Langevin equation in $c$-numbers and show that the latter is amenable to a theoretical analysis in terms of the classical theory of non-Markovian dynamics. The corresponding Fokker-Planck, diffusion and the Smoluchowski equations are the {\it exact} quantum analogues of their classical counterparts. The present work is {\it independent} of path integral techniques. The theory as developed here is a natural extension of its classical version and is valid for arbitrary temperature and friction (Smoluchowski equation being considered in the overdamped limit).Comment: RevTex, 16 pages, 7 figures, To appear in Physical Review E (minor revision

The precursor molecule of A V&lambda; II-immunoglobulin light chain-derived amyloid fibril protein circulates precleaved.

The putative precursor molecule of a human AL type amyloid fibril protein was isolated from an ultrafiltrate after hemofiltration. Subsequennt separation of this protein was achieved by high performance liquid chromatography (HPLC) after reduction and carboxymethylation of the disulfide bonds. The protein was separated into several fractions which were further analyzed by automatic amino acid sequence determination. It was deduced from the sequence data that the precursor molecule is an immunoglobulin L-chain of the &lambda;-type. The V-region of this protein is most closely related to the proteins of subgroup II. Internal splits occurred in the molecule after lysine residues in positions 110, 129 and 179. The predominant fragment commences with either serine or alanine in position 9 and extends to a serine in position 65 of the V-region. Tryptic peptides generated from the fragments cover nearly the entire V- and C-region of the L-chain, with the exception of positions 1-8, from which no peptide has been isolated

An unusual insertion in the third hypervariable region of a human &kappa;-immunoglobulin light chain.

The complete amino acid sequence of the variable region of Bence-Jones protein Mev. from a patient suffering from multiple myeloma and generalized amyloidosis is presented. The amino acid sequence of the Bence-Jones protein Mev. is related to other human kappa-immunoglobulin L-chains of subgroup I. With valine established in Position 191 of the constant region, it is of the Inv (3) allotype. Two types of the Bence-Jones protein Mev. were found, one beginning with the typical N-terminal aspartic acid, and another lacking the N-terminal tripeptide and commencing with methionine in Position 4. A unique insertion of glutamic acid after Position 95 was found in the Bence-Jones protein. This is the position where the V- and J-gene segments join. The J-region of Bence-Jones protein Mev. exhibits some marked differences to the five J-regions recently established by nucleic acid sequencing. This suggests, that there must be considerable polymorphism in human kappa-J-genes. The amyloid fibril protein from the same patient (A Mev.) has also been sequenced up to Position 27. It was found to be identical to the sequence of Bence-Jones protein Mev. commencing with aspartic acid. The molecular mass of the amyloid fibril protein was found to be between 11 000 and 12 000 Da as estimated by gelfiltration and dodecyl sulfate-polyacrylamide electrophoresis

Is the formation of AL-type amyloid promoted by structural peculiarities of immunoglobulin L-chains? Primary structure of an amyloidogenic &lambda;-L-chain (BJP-ZIM).

A Bence-Jones protein (Protein ZIM) was isolated from the urine of a patient with myeloma-associated amyloidosis. The amino-acid sequence of the variable region of the carboxymethylated protein was established by automatic stepwise degradation of the enzymatically deblocked protein and tryptic peptides thereof. The protein is of the &lambda;-type of human immunoglobulin L-chains and is closely homologous to subgroup I. In the course of the tryptic digestion a precipitate was formed which showed properties characteristic of amyloid, such as staining with Congo red and green birefringence in polarized light. High-performance liquid chromatography was applied to separate these peptides. The precipitate consists of two peptides which coincide with position 19-45 of the variable and 129-140 of the costant part, respectively. Possible implications of this finding are discussed in the context of amyloid formation after limited proteolytic digestion

Idiopathic amyloidosis in the stone marten (Martes foina): Identification of amyloid fibril proteins in tissue sections using the immunoperoxidase technique.

Amyloidfibrillen-Proteine, isoliert aus der Milz eines Steinmarders (Martes foina, Exleben) mit idiopathischer Amyloidose, zeigen &Auml;hnlichkeit mit dem Amyloid-A-Protein. Ein Antiserum gegen diese Proteine kann die hier untersuchten Amyloid-Ablagerungen mit Hilfe der Immunperoxidase-Technik an formalin-fixierten und paraffin-eingebetteten Gewebeschnitten identifizieren