A novel method for multiplex protein biomarker analysis of human serum using quantitative MALDI mass spectrometry.

In this work, we have extended our previously proposed approach for determining protein concentrations in human serum (using MALDI-TOF mass spectrometry) to include simultaneous analysis of several proteins associated with acute inflammation (alpha-2-macroglobulin, fetuin-A, serum amyloid A1). This technique can be used to diagnose systemic inflammation and provides results in 4-5 h. The developed approach was verified using standard immunological methods (ELISA).

[The morbidity with temporary disability and its regional characteristics in the Russian Federation in 2000-2018].

The article presents the results of analysis of dynamics of morbidity of working population with temporary disability in the Russian Federation in 2000-2018 according its causes, assessment of gender and age differences and in the context of Federal Okrugs and subjects The Russian Federation. The significant changes in rate and duration of temporary disability indices on National and Regional levels are considered. The absence of differences in structure of causes and average duration of morbidity with temporary disability is analyzed.

[The actual problems of planning of obstetric-gynecologic care in The Russian Federation].

The purpose of the study was to analyze normative legal documents and their modifications in order to determine the labor standards of medical personnel in case of rendering and planning obstetric gynecological care in the Russian Federation, including standards of number of medical personnel in medical organizations and modes of operation of various types. The materials of the study were normative legal documents presented at the WEB-portal "garant.ru".

A mass spectrometric approach to study the interaction of amyloid β peptides with human α-2-macroglobulin.

We used MALDI-MS to study the interaction of amyloid β (Aβ) peptides with alpha-2-macroglobulin (α2M). The binding of amyloid beta (Aβ) peptides to alpha-2-macroglobulin (α2M) was found to inhibit the ability of trypsin to cleave out the peptide α2M 705-715 (Pep-α2M) from α2M. This was observed with both purified α2M and α2M in human serum.

Quench me if you can: Alpha-2-macroglobulin trypsin complexes enable serum biomarker analysis by MALDI mass spectrometry.

One of the main functions of alpha-2-macroglobulin (A2M) in human blood serum is the binding of all classes of protease. It is known that trypsin, after such interaction, possesses modified proteolytic activity. Trypsin first hydrolyzes two bonds in A2M's 'bait region', and the peptide VGFYESDVMGR is released from A2M.

[The Morbidity of Children Population and Its Regional Characteristics in the Russian Federation in 2012-2018].

The article presents the analysis of results of the study of incidence and prevalence of children diseases in Russia in 2012-2018 including structure of diseases classes, regional characteristics in the Federal okrugs and regions and assessment of chronization coefficient. The significant changes are established in incidence cases rate by disease classes in the Federal districts and regions, in dynamics of chronization coefficient, and their absence in morbidity structure.

[The persistent disability of population in the Russian Federation: analysis and assessment of regional characteristics].

The disability is one of the main indices of public health, along with medical and demographic characteristics, morbidity and physical development that characterizes level of social economic development and is a major problem of health and social care authorities. The availability of statistical data and analysis of problem of population disability will allow to properly plan activities of various administrative bodies. The article presents trends of persistent disability in the Russian Federation during the studied period.

[The complex evaluation of target indices population health in the Central Federal Okrug of the Russian Federation].

The article presents the results of analysis of values and dynamics of changes in indicators of fertility rate, expected life expectancy, total and infant mortality, able-bodied mortality, mortality of circulatory system diseases, neoplasms, and road traffic accidents in 18 subjects of the Central Federal Okrug of the Russian Federation in 2015-2018. The results of comparative analysis of factual values of mentioned indicators with values of target indicators approved by the "Health care Development Strategy in the Russian Federation for period up to 2025" (2019) are presented. The necessary scope of correction of existing discrepancies are established.

Absolute Quantitation of Proteins by Acid Hydrolysis Combined with Amino Acid Detection by Mass Spectrometry.

Amino acid analysis is among the most accurate methods for absolute quantification of proteins and peptides. Here we combine acid hydrolysis with the addition of isotopically labeled standard amino acids and analysis by mass spectrometry for accurate and sensitive protein quantitation. Quantitation of less than 10 fmol of protein standards with errors below 10% has been demonstrated using this method.

Pollen development in Rhododendron in relation to winter dormancy and bloom time.

Microsporogenesis and microgametogenesis of Rhododendron ledebourii (semi-deciduous), Rhododendron luteum (deciduous), and Rhododendron catawbiense (evergreen) were studied by light and electron microscopies in order to determine the stages of pollen development in relation to period of winter dormancy and bloom time throughout an annual growth cycle. Development of generative organs starts in June in R. ledebourii and in July in R.

A conservative mutant of a proteolytic fragment produced during fibril formation enhances fibrillogenesis.

The fibrillogenesis of a peptide corresponding to residues 35-51 of human α-lactalbumin (¹GYDTQAIVENNESTEYG¹⁷) can be dramatically enhanced by the addition of a tetrapeptide TDYG homologous to its C-terminus (TEYG). Generation of spontaneous hydrolytic products similar to this peptide was demonstrated by mass-spectrometry analysis of GYDTQAIVENNESTEYG peptide solution components during fibrillogenesis. Possible mechanisms and roles of short peptides in protein metabolism are discussed.

[The scope and structure of ambulatory polyclinic visits of physicians in the Russian Federation in 2009-2011].

The article presents the results of structural functional analysis of public statistic data concerning the appealability of population the Russian Federation for ambulatory polyclinic care in health institutions of Minzdrav of Russia in 2009-2011. The study was targeted to identify the institutions, the volume, the specialists, the groups of population and purpose of provided medical care. It is demonstrated that during three years the significant differences in volume and structure of ambulatory polyclinic care used per capita between adults and children, urban and rural residents still are present.

[The emergency surgical care in the Russian Federation].

The article presents the results of providing emergency surgical care in case of acute diseases of abdominal organs and extra uterine pregnancy to population of the Russian Federation in 2000-2010. The analysis also considered time between onset of disease and delivery of patient to hospital, structure of diagnosis, operative activity and indicators of lethality. The preventability of lethal outcome under acute diseases of abdominal organs at the expense of hospitalization is calculated.

[The structural analysis of network of ambulatory polyclinic institutions in the Russian Federation].

The article presents the results of structural analysis of statistic data concerning network, capacity and manpower support of institutions providing ambulatory polyclinic care to population of the Russian Federation. The structure of ambulatory polyclinic institutions including their planning capacity, physicians' and paramedical personnel manpower support and depending on type and administrative subordination level are demonstrated. The mean planning capacity of one conditional ambulatory polyclinic institution is estimated for comparative evaluation of intensity of changes in number of institutions and their capacity.

Absolute quantitation of proteins by acid hydrolysis combined with amino acid detection by mass spectrometry.

Amino acid analysis is among the most accurate methods for absolute quantification of proteins and peptides. Here, we combine acid hydrolysis with the addition of isotopically labeled standard amino acids and analysis by mass spectrometry for accurate and sensitive protein quantitation. Quantitation of less than 10 fmol of protein standards with errors below 10% has been demonstrated using this method.

ESI-MS studies of silver ion competitive interaction with cysteine-containing peptides and sulfur-containing amino aсids.

The paper deals with investigation of silver ion interaction with sulfur-bearing amino acids and cysteine-bearing peptides using an electrospray ionisation orthogonal ion introduction time-of-flight (ESI-o-TOF) mass spectrometer. It has been shown that Cys and Hcy demonstrate the largest affinity for silver, both in relation to methionine and cysteine residues in peptides. The studies have for the first time revealed the effect of predominant forming of ions containing two silver atoms per a sulfhydryl group of cysteine-bearing peptides if the nearest microenvironment does not hinder this.

The N-domain of angiotensin-converting enzyme specifically hydrolyzes the Arg-5-His-6 bond of Alzheimer's Abeta-(1-16) peptide and its isoAsp-7 analogue with different efficiency as evidenced by quantitative matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

Chronic imbalance between production and degradation of the human amyloid-beta peptide (Abeta) is assumed to play an important role in pathogenesis of Alzheimer's disease (AD). Post-translational modifications of Abeta could influence its interactions with specifically cleaving proteases and, therefore, perturb the Abeta homeostasis. The angiotensin-converting enzyme (ACE) was previously shown to degrade non-modified Abeta in vitro and in cells.

Novel repressor of the human FMR1 gene - identification of p56 human (GCC)(n)-binding protein as a Krüppel-like transcription factor ZF5.

A series of relatively short (GCC)(n) triplet repeats (n = 3-30) located within regulatory regions of many mammalian genes may be considered as putative cis-acting transcriptional elements (GCC-elements). Fragile X-mental retardation syndrome is caused by an expansion of (GCC)(n) triplet repeats within the 5'-untranslated region of the human fragile X-mental retardation 1 (FMR1) gene. The present study aimed to characterize a novel human (GCC)(n)-binding protein and investigate its possible role in the regulation of the FMR1 gene.

Absolute quantitation of proteins by a combination of acid hydrolysis and matrix-assisted laser desorption/ionization mass spectrometry.

Quantitation by mass spectrometry is increasingly used to monitor protein levels in biological samples. Most of the current methods are based on the relative comparison of protein quantities but are not suited for the determination of the absolute amount of a given protein. Here we describe a method for the absolute quantitation of proteins that is based on amino acid analysis by matrix-assisted laser desorption/ionization mass spectrometry.

Towards the standard-module approach to disulfide-linked polypeptide nanostructures. I. Methodological prerequisites and mass spectrometric characterization of the test two-loop structure.

Potentially biologically-active nanostructures can be created from single chains of unmodified peptides by cross-linking different regions of the chain by disulfide bonds and cleaving the chain at specified sites to obtain the final configuration. The availability of techniques for assembly and characterization of such structures was tested on a two-loop structure created from a 21-residue linear peptide. Directed intra-molecular disulfide bond formation was performed by inserting partial sequences favoring intra-molecular SS bond formation ("loops") separated by partial sequences disfavoring such a process ("spacers") into the precursor sequence.

Comparative study of the action of bovine duodenal proteinases (duodenases) on polypeptide substrates.

A comparative study of substrate specificity of bovine duodenal proteinases--chymotrypsin-like duodenase (ChlD) and dual-specificity duodenase (dsD)--was carried out using oligopeptide substrates (human proinsulin, glucagon, melittin, angiotensinogen fragment 1-14). ChlD displayed mainly chymotrypsin-like properties towards these substrates, hydrolyzing peptide bonds carboxy-terminally to bulky aliphatic or aromatic residues. In melittin, ChlD additionally cleaved peptide bonds after Thr and Ser residues.

Quantitation of peptides and proteins by matrix-assisted laser desorption/ionization mass spectrometry using (18)O-labeled internal standards.

A method for quantitating proteins and peptides in the low picomole and sub-picomole range has been developed using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) with internal (18)O-labeled standards. A simple procedure is proposed to produce such internal standards for the tested sample by enzymatic hydrolysis of the same sample (with known concentration) in (18)O-water. A mathematical algorithm was developed which uses the isotopic patterns of the substance, the internal standard, and the substance/internal standard mixture for accurate quantitation of the substance.

Subcellular localization, substrate specificity and crystallization of duodenase, a potential activator of enteropeptidase.

Duodenase, a serine protease from bovine duodenum mucosa, was located in endoplasmic reticulum, the Golgi secretory granules of epithelial cells and ducts of Brunner's glands by the A-gold immunocytochemical method. Duodenase exhibits trypsin-like and chymotrypsin-like specificities with a preference for substrates having lysine at the P1 and proline at the P2 positions. The kinetic constants for the hydrolysis of 21 potential duodenase substrates are reported.

A novel guanyl-preferable ribonuclease of Bacillus polymyxa: isolation and characterization of the enzyme.

Three forms of the extracellular alkaline ribonuclease of B. polymyxa (RNases Bpo I, Bpo II and Bpo III) were obtained in the homogeneous states. Relative molecular weights, N- and C-terminal amino acid sequences of the proteins were determined.