Relationship of Acylcarnitines to Myocardial Ischemic Remodeling and Clinical Manifestations in Chronic Heart Failure.

BACKGROUND: Progressive myocardial remodeling (MR) in chronic heart failure (CHF) leads to aggravation of systolic dysfunction (SD) and clinical manifestations. Identification of metabolomic markers of these processes may help in the search for new therapeutic approaches aimed at achieving reversibility of MR and improving prognosis in patients with CHF. METHODS: To determine the relationship between plasma acylcarnitine (ACs) levels, MR parameters and clinical characteristics, in patients with CHF of ischemic etiology (n = 79) and patients with coronary heart disease CHD (n = 19) targeted analysis of 30 ACs was performed by flow injection analysis mass spectrometry. RESULTS: Significant differences between cohorts were found for the levels of 11 ACs. Significant positive correlations (r > 0.3) between the medium- and long-chain ACs (MCACs and LCACs) and symptoms (CHF NYHA functional class (FC); r = 0.31-0.39; p < 0.05); negative correlation (r = -0.31-0.34; p < 0.05) between C5-OH and FC was revealed. Positive correlations of MCACs and LCACs (r = 0.31-0.48; p < 0.05) with the left atrium size and volume, the right atrium volume, right ventricle, and the inferior vena cava sizes, as well as the pulmonary artery systolic pressure level were shown. A negative correlation between C18:1 and left ventricular ejection fraction (r = -0.31; p < 0.05) was found. However, a decrease in levels compared to referent values of ACs with medium and long chain lengths was 50% of the CHF-CHD cohort. Carnitine deficiency was found in 6% and acylcarnitine deficiency in 3% of all patients with chronic heart disease. CONCLUSIONS: ACs may be used in assessing the severity of the clinical manifestations and MR. ACs are an important locus to study in terms of altered metabolic pathways in patients with CHF of ischemic etiology and SD. Further larger prospective trials are warranted and needed to determine the potential benefits to treat patients with CV diseases with aberrate AC levels.

Geographic and Ethnic Variations in Serum Concentrations of Legacy Persistent Organic Pollutants among Men in the Nenets Autonomous Okrug, Arctic Russia.

The overwhelming majority of Arctic biomonitoring studies in humans include either pregnant or non-pregnant women of reproductive age while little attention is paid to toxic compounds concentrations in men. This study contributes with information of the present amounts of persistent organic pollutants (POPs) in men living in Arctic Russia. We studied the serum concentrations of 11 polychlorinated biphenyl (PCB) congeners and 17 organochlorine pesticides (OCPs) and some of their metabolites in samples collected from 92 adult men (mean age 43 years) from seven different settlements in Nenets Autonomous Okrug (NAO). The median concentrations of individual PCB congeners increased in the order PCB 183, PCB 180, PCB 118, PCB 138, PCB 153. The concentrations of o, p'-DDD, p, p'-DDD, aldrin, mirex and 1,2,3,5-TCB were in most cases below the quantification limit. The observed concentrations of PCBs and chlorinated pesticides were in the same range as those found in similar groups of women of these territories, but lower than of men in other Arctic countries. However, significant geographic differences between the settlements were observed with exceptionally high concentrations of PCBs in the Islands group. The highest serum ∑PCBs and ß-HCH levels were observed in adult males aged 60-78 years. We found significant variations in serum concentrations of POPs across settlements and ethnic groups with exceptionally high concentrations of PCBs among the residents of the Arctic islands. At the same time, our findings suggest a considerable decrease in serum concentration of POPs over the last decade.

Is supramolecular filament chirality the underlying cause of major morphology differences in amyloid fibrils?

The unique enhanced sensitivity of vibrational circular dichroism (VCD) to the formation and development of amyloid fibrils in solution is extended to four additional fibril-forming proteins or peptides where it is shown that the sign of the fibril VCD pattern correlates with the sense of supramolecular filament chirality and, without exception, to the dominant fibril morphology as observed in AFM or SEM images. Previously for insulin, it has been demonstrated that the sign of the VCD band pattern from filament chirality can be controlled by adjusting the pH of the incubating solution, above pH 2 for "normal" left-hand-helical filaments and below pH 2 for "reversed" right-hand-helical filaments. From AFM or SEM images, left-helical filaments form multifilament braids of left-twisted fibrils while the right-helical filaments form parallel filament rows of fibrils with a flat tape-like morphology, the two major classes of fibril morphology that from deep UV resonance Raman scattering exhibit the same cross-ß-core secondary structure. Here we investigate whether fibril supramolecular chirality is the underlying cause of the major morphology differences in all amyloid fibrils by showing that the morphology (twisted versus flat) of fibrils of lysozyme, apo-α-lactalbumin, HET-s (218-289) prion, and a short polypeptide fragment of transthyretin, TTR (105-115), directly correlates to their supramolecular chirality as revealed by VCD. The result is strong evidence that the chiral supramolecular organization of filaments is the principal underlying cause of the morphological heterogeneity of amyloid fibrils. Because fibril morphology is linked to cell toxicity, the chirality of amyloid aggregates should be explored in the widely used in vitro models of amyloid-associated diseases.

Quantitative methods for structural characterization of proteins based on deep UV resonance Raman spectroscopy.

Here we report on novel quantitative approaches for protein structural characterization using deep UV resonance Raman (DUVRR) spectroscopy. Specifically, we propose a new method combining hydrogen-deuterium (HD) exchange and Bayesian source separation for extracting the DUVRR signatures of various structural elements of aggregated proteins including the cross-beta core and unordered parts of amyloid fibrils. The proposed method is demonstrated using the set of DUVRR spectra of hen egg white lysozyme acquired at various stages of HD exchange. Prior information about the concentration matrix and the spectral features of the individual components was incorporated into the Bayesian equation to eliminate the ill-conditioning of the problem caused by 100% correlation of the concentration profiles of protonated and deuterated species. Secondary structure fractions obtained by partial least squares (PLS) and least squares support vector machines (LS-SVMs) were used as the initial guess for the Bayessian source separation. Advantages of the PLS and LS-SVMs methods over the classical least squares calibration (CLSC) are discussed and illustrated using the DUVRR data of the prion protein in its native and aggregated forms.

Structural variations in the cross-beta core of amyloid beta fibrils revealed by deep UV resonance Raman spectroscopy.

Understanding fibrillogenesis at a molecular level requires detailed structural characterization of amyloid fibrils. The combination of deep UV resonance Raman (DUVRR) spectroscopy and post mortem hydrogen-deuterium exchange (HX) was utilized for probing parallel vs antiparallel beta-sheets in fibrils prepared from full-length Abeta(1-40) and Abeta(34-42) peptides, respectively. Using previously published structural data based on solid-state NMR analysis, we verified the applicability of Asher's approach for the quantitative characterization of peptide conformation in the Abeta(1-40) fibril core. We found that the conformation of the parallel beta-sheet in the Abeta(1-40) fibril core is atypical for globular proteins, while in contrast, the antiparallel beta-sheet in Abeta(32-42) fibrils is a common structure in globular proteins. In contrast to the case for globular proteins, the conformations of parallel and antiparallel beta-sheets in Abeta fibril cores are substantially different, and their differences can be distinguished by DUVRR spectroscopy.

Detection of disseminated intravascular coagulation with the help of the conception of constant intravascular microcoagulation.

The possibility of intravascular blood coagulation existence in the microvascular vessels and capillaries without the presence of a large thrombus in the arteries and veins has been known from the middle of 19th century. It is impossible to know exactly about the prevalence of this pathology, because there is a jumble in terminology that does not help statistics to be exact. One of the reasons of so high mortality from disseminated intravascular coagulation (DIC) is due to the impossibility to always make exact diagnosis, and as M. Levi thinks it is provoked in the absence of generally accepted idea of DIC syndrome. We investigated these markers and the intensity of intravascular blood coagulation in a number of patients. Our understanding of the problems of DIC was formulated on the grounds of a thirty-year study of the problem involving over 1,500 patients. Thereby, the conception of constant intravascular microcoagulation (CIMC) was developed with the following aims: to report the existing material and bring to researchers and doctors in practice information about the presence of the phenomenon of CIMC and to resolve debatable questions of definitions and practical usage of up-to-date information about DIC with the help of CIMC conception.

Penicillin and vitamin A as possible therapeutic agents in pityriasis rubra pilaris.

Pityriasis rubra pilaris (PRP) is a rare skin disorder with versatile clinical presentations. A 62-year-old Caucasian woman with progressive erythroderma and classic adult (type I) PRP is presented. Treatment with systemic steroids and methotrexate produced no improvement. Clinical remission was achieved after systemic therapy with penicillin (both intravenous and intramuscular) and vitamin A. The therapy of PRP is reviewed, focusing on a possible infectious genesis of PRP as well as the role of antibiotics in its management.

Mechanism of fibril formation by a 39-residue peptide (PAPf39) from human prostatic acidic phosphatase.

PAPf39 is a 39-residue peptide fragment from the sequence of human prostatic acidic phosphatase. This peptide was shown to form amyloid-like fibrils, which have been implicated in facilitating semen-mediated HIV transmission. Thus understanding molecular details of PAPf39 peptide fibril formation may aid in elucidating the mechanism of how PAPf39 fibrils are involved in HIV etiology. To this end, the kinetics of PAPf39 peptide fibrillization was studied using a battery of biophysical methods (atomic force microscopy, ThT fluorescence assays, far-UV circular dichroism spectroscopy, deep-UV resonance Raman spectroscopy, size exclusion chromatography, analytical ultracentrifugation, and small-angle X-ray scattering). It has been shown that fibril formation follows a nucleation-dependent elongation mechanism. Several critical factors for fibrillization have been identified. It was shown that agitation and/or seeding is required for fibril formation at 37 degrees C and neutral pH, with an additional requirement of a salt concentration above approximately 100 mM. Fibril formation by the PAPf39 peptide is inhibited by low pH or by low salt concentration at neutral pH. These observations suggest that the nucleation and fibrillization of the PAPf39 peptide are a tug-of-war between the interactions formed upon agitation and the electrostatic interactions, modulated by pH and salt concentration.

Reversible thermal denaturation of a 60-kDa genetically engineered beta-sheet polypeptide.

A de novo 687-amino-acid residue polypeptide with a regular 32-amino-acid repeat sequence, (GA)(3)GY(GA)(3)GE(GA)(3)GH(GA)(3)GK, forms large beta-sheet assemblages that exhibit remarkable folding properties and, as well, form fibrillar structures. This construct is an excellent tool to explore the details of beta-sheet formation yielding intimate folding information that is otherwise difficult to obtain and may inform folding studies of naturally occurring materials. The polypeptide assumes a fully folded antiparallel beta-sheet/turn structure at room temperature, and yet is completely and reversibly denatured at 125 degrees C, adopting a predominant polyproline II conformation. Deep ultraviolet Raman spectroscopy indicated that melting/refolding occurred without any spectroscopically distinct intermediates, yet the relaxation kinetics depend on the initial polypeptide state, as would be indicative of a non-two-state process. Thermal denaturation and refolding on cooling appeared to be monoexponential with characteristic times of approximately 1 and approximately 60 min, respectively, indicating no detectable formation of hairpin-type nuclei in the millisecond timescale that could be attributed to nonlocal "nonnative" interactions. The polypeptide folding dynamics agree with a general property of beta-sheet proteins, i.e., initial collapse precedes secondary structure formation. The observed folding is much faster than expected for a protein of this size and could be attributed to a less frustrated free-energy landscape funnel for folding. The polypeptide sequence suggests an important balance between the absence of strong nonnative contacts (salt bridges or hydrophobic collapse) and limited repulsion of charged side chains.