Study of Human Fibrinogen Oxidative Modification using Differential Scanning Calorimetry.

For the first time, with the aid of differential scanning calorimetry, the thermal denaturation of fibrinogen under induced oxidation was studied. All fibrinogen structural elements detected by DSC (D region, αC-domain, and E region) are subjected to oxidation. Structural changes in fibrinogen molecule were characterized by the denaturation temperature, denaturation enthalpy, and van't Hoff enthalpy.

Oxidation-induced modification of the fibrinogen polypeptide chains.

By using the mass-spectrometry method, the oxidative modifications of the fibrinogen Aα, Bß, and γ polypeptide chains induced by its oxidation have been studied. The αC-region has been proven to be the most vulnerable target for the oxidizer (ozone) as compared with the other structural elements of the Aα chain. The Bß chain mapping shows that the oxidative sites are localized within all the structural elements of the chain in which the ß-nodule exhibits high susceptibility to oxidation. The γ chains are the least vulnerable to the oxidizer action. The results obtained demonstrate convincingly that the self-assembly centers dealing with interactions of knob "A": hole "a" are not involved in oxidative modification. It is concluded that the numerous oxidative sites revealed are mainly responsible for inhibiting lateral aggregation of protofibrils. The part of amino acid residues subjected to oxidation is supposed to carry out the antioxidant function.

Modification of the catalytic subunit of plasma fibrin-stabilizing factor under induced oxidation.

For the first time, by using mass-spectrometry method, the oxidation-mediated modification of the catalytic FXIII-A subunit of plasma fibrin-stabilizing factor, pFXIII, has been studied. The oxidative sites were identified to belong to all structural elements of the catalytic subunit: the ß-sandwich (Tyr104, Tyr117, and Cys153), the catalytic core domain (Met160, Trp165, Met266, Cys328, Asp352, Pro387, Arg409, Cys410, Tyr442, Met475, Met476, Tyr482, and Met500), the ß-barrel 1 (Met596), and the ß-barrel 2 (Met647, Pro676, Trp692, Cys696, and Met710), which correspond to 3.9%, 1.11%, 0.7%, and 3.2%, respectively, of oxidative modifications as compared to the detectable amounts of amino acid residues in each of the structural domains. Lack of information on some parts of the molecule may be associated with the spatial unavailability of residues, complicating analysis of the molecule. The absence of oxidative sites localized within crucial areas of the structural domains may be brought about by both the spatial inaccessibility of the oxidant to amino acid residues in the zymogen and the screening effect of the regulatory FXIII-B subunit.

Modification of human serum albumin under induced oxidation.

For the first time, by using the complex of physicochemical methods (mass-spectrometry, differential scanning calorimetry, spectrofluorimetry, method of spectral and fluorescent probes, dynamic light scattering, and UV spectrophotometry), the oxidation-mediated modification of chemical and spatial structure of albumin has been studied. All albumin structural regions are subjected to oxidation, methionine and aromatic amino acids primarily involved in oxidation. The albumin melting shows a decrease in thermal stabilization of the structure and changing of aggregation upon oxidation. The change in physical and chemical properties of albumin under different quantity of the oxidizer has been analyzed.

The strengthening role of D:D interactions in fibrin self-assembly under oxidation.

The effect on ozone-induced oxidation on the self-assembly of fibrin in the presence of fibrin-stabilizing factor FXIIIa of soluble cross-linked fibrin oligomers was studied in a medium containing moderate urea concentrations. It is established that fibrin oligomers were formed by the protofibrils cross-linked through γ-γ dimers and the fibrils additionally cross-linked by through α-polymers. The oxidation promoted both the accumulation of greater amounts of γ-γ dimers and the formation of protofibrils, fibrils, and their dissociation products emerging with increasing urea concentrations, which have a high molecular weight. It is concluded that the oxidation enhances the axial interactions between D-regions of fibrin molecules.

The oxidative modification of cellular fibrin-stabilizing factor.

For the first time, the induced oxidative modification of cellular fibrin-stabilizing factor (cFXIII) has been studied. According to the electrophoresis analysis, the conversion of oxidized cFXIII into FXIIIa resulted in producing the enzyme that significantly lost the initial enzymatic activity. At the same time, FXIIIa subjected to induced oxidation was completely devoid of enzymatic activity. The results of FTIR spectroscopy showed that the oxidation of cFXIII or FXIIIa was accompanied by profound changes both in chemical and spatial structures of the protein. The results of this study are in good agreement with our earlier assumption regarding the antioxidant role of the regulatory subunits B of plasma fibrin-stabilizing factor.

[Postoperative applications of the fast track technology in patients with herniated intervertebral discs of the lumbosacral spine]. / Primenenie tekhnologii bystrogo vosstanovleniya posle khirurgicheskikh vmeshatel'stv u patsientov s gryzhami mezhpozvonkovykh diskov poyasnichno-kresttsovogo otdela pozvonochnika.

TOPICALITY: The fast track technology means a complex of targeted measures involving rational preoperative preparation, minimally invasive surgery, regional anesthesia and short-acting anesthetics, and early postoperative rehabilitation. Elucidating the possibility of applying the fast track technology in neurosurgery, in particular in spinal surgery, is extremely topical. This is associated with the epidemiological data and the fact that minimally invasive techniques used in neurosurgery are highly expensive. AIM: The study objective was implementation of the fast track technology and subsequent analysis of its use after surgery in patients with herniated intervertebral discs of the lumbosacral spine. MATERIAL AND METHODS: The fast track technology following spinal surgery was implemented at the Clinical Hospital of the Presidential Administration of the Russian Federation and the Neurosurgical Department of the Clinical Hospital № 1 of the Presidential Administration of the Russian Federation using an algorithm of technology application. The study included 48 patients who underwent surgical treatment for herniated intervertebral discs of the lumbosacral spine between January and July 2015. RESULTS: An analysis of pain severity using the Visual Analog Scale demonstrated a slight decrease (10%) in a group of patients who were subjected to the fast track technology, at discharge and at 1 month after surgery; there was no difference in longer follow-up. An analysis of the functional status using the Oswestry index and Roland-Morris scale demonstrated that patients of the study group had faster and more efficient recovery and an improvement of the functional activity by 20% (p<0.05) compared to those in the control group. An analysis of patient-reported assessment of treatment quality revealed that indicators, such as awareness and pain control, in the study group were highest and amounted to 95% and higher. An analysis of the hospital stay duration showed a decrease in the number of bed-days in an integrated group by 39%, which saved 34 bed-days. CONCLUSION: The fast track technology reduces the degree of surgical aggression, increases surgery safety, and decreases the number of intraoperative complications and hospital stay duration.

[Vertebrology 2.0: an automatic virtual consultation system].

UNLABELLED: The use of computer information and Internet technologies to solve clinical problems becomes trivial but is still a topical and promising direction closely related to the «Healthcare 2.0¼ concept. The methodology for developing virtual patient consultation systems is associated with the capabilities to process obtained data and optimize the choice of optimal tactics for further treatment, taking opportunities of the Internet. The study objective was to develop an automatic virtual consultation system for patients with spine and spinal cord diseases on the basis of the online vertebrologi.ru portal. MATERIAL AND METHODS: 33 signs with different answer variants were selected for advising. On the basis of these signs, an expert advised more than 170 patients. RESULTS AND CONCLUSION: On the basis of consultation analysis, a set of rules was developed to automatically generate a consultation text, depending on selected sign values. Currently, the automatic virtual consultation system, which was developed jointly by the Institute for Systems Analysis, Burdenko Neurosurgical Institute, and Volynskaya Clinical Hospital №1, operates online on the vertebrologi.ru portal as one of its modules.

X-Linked Recessive form of Nephrogenic Diabetes Insipidus in a 7-Year-Old Boy.

Nephrogenic diabetes insipidus (NDI) is caused by the inability of renal collecting duct cells to respond to arginine vasopressin (AVP)/antidiuretic hormone (ADH). We present the case of a 7-year-old boy with a history of excretion of large amounts of dilute urine and polydipsia since infancy. The boy had several vomiting episodes with mild dehydration during the first 3 years of life. There was no evidence of headaches, dizziness or visual problems. He drinks between 2 and 3 L/day and has 24-hour diuresis of 2 liters, now. He has prepubertal appearance with appropriate weight [+0.85 standard deviation score (SDS)] and height (+0.15 SDS) for his age. His intelligence was also normal. The water deprivation test showed low urine osmolality after 8 hours of dehydration. After desmopressin administration, urine osmolality remained low. Serum osmolality was in the normal range for sex and age before and after desmopressin administration. This indicated a nephrogenic form of diabetes insipidus. Molecular analyses revealed a P286L [p.Pro(CCC)286Leu(CTC)] mutation in the AVPR2 gene, that was inherited from his mother. This patient is the first case with genetically confirmed X-linked inherited form of NDI in the Republic of Macedonia. Molecular analysis confirmed the clinical diagnosis and enabled genetic advice for this family.

Ozone-induced oxidative modification of fibrinogen molecules.

Ozone-induced oxidation of fibrinogen has been investigated. The conversion of oxidized fibrinogen to fibrin catalyzed either by thrombin or by a reptilase-like enzyme, ancistron, in both cases is accompanied by production of gels characterized by a higher weight/length ratio of fibrils in comparison with the native fibrin gels. IR spectra of the D and E fragments isolated from unoxidized and oxidized fibrinogen suggest a noticeable transformation of functional groups by oxidation. A decrease in content of N-H groups in the peptide backbone and in the number of C-H bonds in aromatic structures, as well as a decrease in the intensity of the C-H valence vibrations in aliphatic fragments CH2 and CH3 were found. The appearance in the differential spectra of the D fragments of rather intense peaks in the interval of 1200-800 cm(-1) clearly indicates the interaction of ozone with amino acid residues of methionine, tryptophan, histidine, and phenylalanine. Comparison of the differential spectra for the D and E fragments suggests that fibrinogen fragment D is more sensitive to the oxidant action than fragment E. Using EPR spectroscopy, differences are found in the spectra of spin labels bound with degradation products of oxidized and unoxidized fibrinogen, the D and E fragments, caused by structural and dynamical modifications of the protein molecules in the areas of localization of the spin labels. The relationship between the molecular mechanism of oxidation of fibrinogen and its three-dimensional structure is discussed.

[Estimating ability of dihydroquercetin to inhibit oxidation of fibrinogen by ozone].

The ability of dihydroquercetin to inhibit the oxidation of fibrinogen has been evaluated. It is established that dihydroquercetin inhibits oxidation of fibrinogen by ozone, thus preventing oxidative modification of fibrinogen and preserving its functional activity.

Stages of xylene transforming during carbon particle synthesis.

Xylene is one of the materials that could be used for synthesis of different carbon nanoparticles including perfect carbon spheres with diameters of 1 to 8 microm and ellipsoids. Its changes in the course of the pyrolytic process in a hermetically sealed stainless steal container have been examined by stopping the process at different stage of temperature treatment from 100 degrees C to 600 degrees C. The prepared material is in a liquid phase up to 400 degrees C and its relative weight and optical transmittance changes have been measured. The origins of these changes are traced to solid micro and nanoparticles and their morphology, which was studied by Scanning (SEM) and Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), Electron Probe X-ray Micro Analysis and Energy Dispersive X-ray Spectrometry (EDS), and Fourier Transform Infrared Spectroscopy (FTIR).

[The terminology, classifications and staging of neuroendocrine tumors of the pancreas].

The basic classifications, including the TNM and the WHO's classification of neuroendoctine tumors of the pancreas are highlighted. The WHO's dividing such tumors on G1 and G2 neuroendocrine lesions and G3 neuroendocrine carcinomas is substantiated.

Separation of anthropogenic radionuclides from aqueous environment using raw and modified biosorbents.

In this study, two types of biosorbents were used to remove 137Cs and plutonium isotopes from aqueous solutions - moss (Ptilium crista - castrensis) and oak sawdust (Quercus robur), both in the form of natural and modified state. Sorbent modification significantly increases the sorbent surface area (for moss sorbents - from 4.0 to 47.2 m2/g, and for sawdust sorbents - from 1.1 to 26.3 m2/g), pore volume (from 10-3 to 10-2), concentration and amount of basic cations and anions, as well as active functional groups on the sorbent surface. The main functional groups on the surface of natural sorbents modified with iron hydroxide interacting with analytes are carboxyl and hydroxyl groups. For carbonized sawdust and its subsequent activation with concentrated HCl, in addition to carboxyl and hydroxyl groups, acetyl groups also become active. Carbonated sawdust treated with HCl showed the highest average removal efficiency and sorption capacity for radiocesium and plutonium isotopes in laboratory column experiments - for 137Cs ∼78.6% and ∼196.6 Bq/g and for 239+240Pu ∼83% and ∼41.5 Bq/g, respectively. The moss and moss modified with iron hydroxide also showed good properties of adsorbing plutonium isotopes in field (in-situ) experiments. The best results on the sorption of 137Cs in field experiments were shown by carbonated sawdust activated with HCl, and for isotopes of plutonium - the raw moss and moss modified with iron hydroxide. The results of the study showed that sorbents can be used not only for purification of water from plutonium isotopes but allow the operational sampling and more accurate measurement of radiocesium and plutonium isotopes in the fresh water reservoirs by the dynamic flow method.

Oxidized modification of fragments D and E from fibrinogen induced by ozone.

Ozone-induced free-radical oxidation of fragments D and E from fibrinogen has been studied. The methods of elastic and dynamic light scattering in combination with electrophoresis of unreduced samples have shown the acceleration of enzymatic covalent crosslinking of molecules of oxidation-modified fragment D under the action of factor XIIIa. UV and IR spectroscopy shows that free-radical oxidation of amino acid residues of polypeptide chains catalyzed by ozone affects the cyclic and amino groups, giving rise to generation of mainly oxygen-containing products. Comparison of the IR spectra obtained for the oxidation-modified D and E fragments revealed more significant transformation of functional groups for the D fragment. EPR spectroscopy showed that the rotational correlation time of spin labels bound to the ozonized proteins decreased in comparison with the non-ozonized proteins. The rotation correlation time of the radicals covalently bound to the ozonized D and E fragments suggests that D fragment of fibrinogen is more sensitive to free-radical oxidation followed by local structural changes. Possible causes of different degrees of oxidation for fragments D and E are discussed.

[Sarcomatoid carcinoma of the thymus].

Sarcomatoid carcinomas are rare malignancies composed of epithelial (carcinomatous) and sarcomatous elements. High-grade carcinoma is difficult to diagnose by light optic and immunohistochemical studies. The authors give the data available in the literature on sarcomatoid carcinoma of the thymus and also describe their own observation. Its histological pattern is represented by a combination of carcinomatous and sarcomatous elements with extensive necrotic foci. Immunohistologically, the tumor cells expressed total cytokeratin (AE1/AE3), CD99, and focally epithelial membrane antigen. Some tumor cells were vimentin- and SMA-positive. Markers, such as chromogranin A, bcl-2, bcl-6, S-100 protein and myogenin, were negative.

Self-assembly of fibrin monomers and fibrinogen aggregation during ozone oxidation.

The mechanism of self-assembly of fibrin monomers and fibrinogen aggregation during ozone oxidation has been studied by the methods of elastic and dynamic light-scattering and viscosimetry. Fibrin obtained from oxidized fibrinogen exhibits higher average fiber mass/length ratio compared with native fibrin. Fibrinogen ozonation sharply reduced the latent period preceding aggregation of protein molecules; however, the mechanism of self-assembly of ozonated and non-ozonated fibrinogen cluster was identical. In both cases flexible polymers are formed and reaching a certain critical length they form densely packed structures and aggregate. Using infrared spectroscopy, it has been shown that free radical oxidation of amino acid residues of fibrinogen polypeptide chains catalyzed by ozone results in formation of carbonyl, hydroxyl, and ether groups. It is concluded that fibrinogen peripheral D-domains are the most sensitive to ozonation, which causes local conformational changes in them. On one hand, these changes inhibit the reaction of longitudinal polymerization of monomeric fibrin molecules; on the other hand, they expose reaction centers responsible for self-assembly of fibrinogen clusters.