[Invasive mucormycosis affecting maxillofacial region in oncohematological patients undergoing chemotherapeutic treatment and transplantation of hematopoietic stem cells]. / Invazivnyi mukormikoz s porazheniem organov chelyustno-litsevoi oblasti u onkogematologicheskikh bol'nykh na fone khimioterapevticheskogo lecheniya i transplantatsii gemopoeticheskikh stvolovykh kletok.

The aim of the work is to attract the attention of specialists: dentists, oncologists, hematologists to thorough sanitation of the oral cavity of patients preparing for chemotherapy treatment, to transplantation of hematopoietic stem cells. Two clinical cases described in the article were observed at the R.M. Gorbacheva First Saint-Petersburg State Medical University from 2010 to 2019. They confirm the possibility of the occurrence of infectious complications with damage to the maxillofacial region caused by rare pathogens of invasive mycosis, which debuted as an odontogenic inflammatory process. The success of the treatment of Invasive Mycosis depends on early diagnosis and antimycotic therapy; active surgical tactics in relation to the affected tissues in a controlled course of the underlying disease and the restoration of effective hematopoiesis.

High-resolution and high-sensitivity absorption spectroscopy in external optical resonators with fast frequency tuning.

The effect of the laser frequency tuning rate on a weak optical absorption line profile ~(10-5-10-7) cm-1 under conditions when the molecules were in a high-quality optical resonator was studied. The authors used a diode laser and an analytical cavity with two pairs of mirrors with reflectivity of 99% and 99.98% in the ~1.4 µm region. Water vapor at reduced pressure (0.03-1) Torr served as an absorbing medium. A high spectral resolution was obtained by directing laser radiation into the cavity with a small offset relative to its axis (off-axis ICOS). The frequency tuning rate was varied within (102-103) cm-1 s-1. With the increase of the rate, a shift and asymmetry of the Doppler absorption profile were observed. When the tuning direction was changed and the rate was kept the same, the effect preserved in time and mirrored symmetrically on the frequency scale. The measurements were consistent with calculations that took into account the finite lifetime of photons in the cavity and the real ratio of the effective optical path to the coherence length of the laser radiation. Limitations on the frequency tuning rate were discussed using quantitative absorption spectroscopy methods for measuring molecule concentrations.

Biocatalytic conversion of poultry processing leftovers: Optimization of hydrolytic conditions and peptide hydrolysate characterization.

Peptide hydrolysate (PH) was produced by deep controllable bioconversion of poultry processing leftovers (broiler necks), by means of a multienzyme composition, containing four commercially available enzyme preparations (Alcalase, Neutrase, Flavourzyme, Protamex). The design of multienzyme composition (MEC) was applied to yield a hydrolysate with adjusted properties, including minimized antigenicity and bitterness. The protein recovery was optimized using Box-Behnken response surface design. The individual and interactive effects of hydrolysis conditions (time, hydromodule and MEC dosage) were studied. The experimental data were analyzed by ANOVA method and a well-predictive, second order polynomial model was developed using multiple regression analysis. Optimal hydrolysis conditions were found to be: hydrolysis time 3 h, hydromodule 2.25 l/kg and dosage of MEC 0.25%. The corresponding predicted value for protein recovery was 75.34%, 2 times higher compared to traditional long-term heating hydrolysis. The PH obtained is a low allergenic product with high antioxidant capacity.

Bubble-detector measurements of neutron radiation in the international space station: ISS-34 to ISS-37.

Bubble detectors have been used to characterise the neutron dose and energy spectrum in several modules of the International Space Station (ISS) as part of an ongoing radiation survey. A series of experiments was performed during the ISS-34, ISS-35, ISS-36 and ISS-37 missions between December 2012 and October 2013. The Radi-N2 experiment, a repeat of the 2009 Radi-N investigation, included measurements in four modules of the US orbital segment: Columbus, the Japanese experiment module, the US laboratory and Node 2. The Radi-N2 dose and spectral measurements are not significantly different from the Radi-N results collected in the same ISS locations, despite the large difference in solar activity between 2009 and 2013. Parallel experiments using a second set of detectors in the Russian segment of the ISS included the first characterisation of the neutron spectrum inside the tissue-equivalent Matroshka-R phantom. These data suggest that the dose inside the phantom is ∼70% of the dose at its surface, while the spectrum inside the phantom contains a larger fraction of high-energy neutrons than the spectrum outside the phantom. The phantom results are supported by Monte Carlo simulations that provide good agreement with the empirical data.

Overview of the Liulin type instruments for space radiation measurement and their scientific results.

Ionizing radiation is recognized to be one of the main health concerns for humans in the space radiation environment. Estimation of space radiation effects on health requires the accurate knowledge of the accumulated absorbed dose, which depends on the global space radiation distribution, solar cycle and local shielding generated by the 3D mass distribution of the space vehicle. This paper presents an overview of the spectrometer-dosimeters of the Liulin type, which were developed in the late 1980s and have been in use since then. Two major measurement systems have been developed by our team. The first one is based on one silicon detector and is known as a Liulin-type deposited energy spectrometer (DES) (Dachev et al., 2002, 2003), while the second one is a dosimetric telescope (DT) with two or three silicon detectors. The Liulin-type instruments were calibrated using a number of radioactive sources and particle accelerators. The main results of the calibrations are presented in the paper. In the last section of the paper some of the most significant scientific results obtained in space and on aircraft, balloon and rocket flights since 1989 are presented.

[Reactivating factor of Luteococcus japonicus subsp. casei: isolation and characterization].

It has been shown that a producer strain of reactivating factor (RF) is identical to a typical strain of Luteococcus japonicus DSM 10546 from the Propionibacteriaceae family according to the physiological and biochemical properties and the sequencing of 16S rRNA fragments. A number of phenotypical differences from the model strain allowed the producer strain to be considered a subspecies of Luteococcus japonicus, and it was named Luteococcus japonicus subsp. casei. At cultivation of the producer, RF is secreted into the medium and plays the role of a signaling molecule. RF antioxidant activities towards various organic radicals may be a possible mechanism of its protective and reactivating effects. Metabolites secreted by the L. casei producer strain into the culture medium were separated by a combination of liquid chromatographies. Four components possessing biological activities were found. The most active one was studied by MALDI-TOF mass spectrometry, which revealed that it is a polypeptide. Primary identification of some amino acid residues was performed. Sugar residues were found in the structure.

Bubble-detector measurements in the Russian segment of the International Space Station during 2009-12.

Measurements using bubble detectors have been performed in order to characterise the neutron dose and energy spectrum in the Russian segment of the International Space Station (ISS). Experiments using bubble dosemeters and a bubble-detector spectrometer, a set of six detectors with different energy thresholds that is used to determine the neutron spectrum, were performed during the ISS-22 (2009) to ISS-33 (2012) missions. The spectrometric measurements are in good agreement with earlier data, exhibiting expected features of the neutron energy spectrum in space. Experiments using a hydrogenous radiation shield show that the neutron dose can be reduced by shielding, with a reduction similar to that determined in earlier measurements using bubble detectors. The bubble-detector data are compared with measurements performed on the ISS using other instruments and are correlated with potential influencing factors such as the ISS altitude and the solar activity. Surprisingly, these influences do not seem to have a strong effect on the neutron dose or energy spectrum inside the ISS.

[Modern methods of examination of ballistic trauma after passing through the barrier].

On the basis of experimental data were studied peculiarities of ballistic of wounds after passing barriers. Authors analyzed forensic medical examination reports concerned about murdered and wounded with gunshots in Saint Petersburg. As research objects were used: simulators of biological materials (block of glycerin soap) and experimental animals. The following bullets were used: automat cartridge 7H22, 7H24 - gauge 5,45x39 mm, pistol cartridge 7H29 - gauge 9,0x21 mm; gun reach - 50 and 100 meters; barriers - steel plates, glass, brickwork. The following assessment of exposure was used: in simulators - according to volumes of temporary cavity; in experimental animals - according to results of morphofunctional researches. Data about damaging action of pistol cartridge 7H22, 7H24 with gauge 5,45 mm and automat cartridges 7H29 and 9,0 mm is received.

[Results of measuring neutrons doses and energy spectra inside Russian segment of the International Space Station in experiment "Matryoshka-R" using bubble detectors during the ISS-24-34 missions].

The paper presents the results of calculating the equivalent dose from and energy spectrum of neutrons in the right-hand crewquarters in module Zvezda of the ISS Russian segment. Dose measurements were made in the period between July, 2010 and November, 2012 (ISS Missions 24-34) by research equipment including the bubble dosimeter as part of experiment "Matryoshka-R". Neutron energy spectra in the crewquarters are in good agreement with what has been calculated for the ISS USOS and, earlier, for the MIR orbital station. The neutron dose rate has been found to amount to 196 +/- 23 microSv/d on Zvezda panel-443 (crewquarters) and 179 +/- 16 microSv/d on the "Shielding shutter" surface in the crewquarters.

Prospective cohort study of six hundred and sixty four revisions of loose failed acetabular implants.

PURPOSE: The purpose of the study was to determine the optimal technique of revision surgery according to the deficiency of acetabular bone to ensure maximum survival of the implant and reduce the risk of complications. METHODS: From January 1992 through May 2012, 664 revisions of failed acetabular total hip components were performed in the joint replacement department of the Moscow Central Scientific and Research Institute (CITO). The patients were divided into three major groups based on the type of the revision implant: group I--cemented polyethylene cups only, group II--acetabular cages and rings, and group III--non-cemented metal cups. In each of these groups, further subdivisions were made based on the Paprosky Classification of the acetabular defects. Failures were classified as early mechanical instability, chronic pain, and deep wound infection. RESULTS: The most satisfactory results--91% were obtained in patients of groups I and III with relatively minor bony acetabular defects (Paprosky classification types 1, 2A and 2B). The most unsatisfactory results--25% were in the cases with greater bone loss (Paprosky classification type 3B in group I and type 2C in group III)-of the unsatisfactory results. Infection was a significant problem in all the groups, but was the highest (8%) in group II. CONCLUSIONS: The study showed that the success of acetabular revisions was directly related to the severity of the bony defects at the time of the operation and to the reconstruction technique applied.

Measurements of the neutron dose and energy spectrum on the International Space Station during expeditions ISS-16 to ISS-21.

As part of the international Matroshka-R and Radi-N experiments, bubble detectors have been used on board the ISS in order to characterise the neutron dose and the energy spectrum of neutrons. Experiments using bubble dosemeters inside a tissue-equivalent phantom were performed during the ISS-16, ISS-18 and ISS-19 expeditions. During the ISS-20 and ISS-21 missions, the bubble dosemeters were supplemented by a bubble-detector spectrometer, a set of six detectors that was used to determine the neutron energy spectrum at various locations inside the ISS. The temperature-compensated spectrometer set used is the first to be developed specifically for space applications and its development is described in this paper. Results of the dose measurements indicate that the dose received at two different depths inside the phantom is not significantly different, suggesting that bubble detectors worn by a person provide an accurate reading of the dose received inside the body. The energy spectra measured using the spectrometer are in good agreement with previous measurements and do not show a strong dependence on the precise location inside the station. To aid the understanding of the bubble-detector response to charged particles in the space environment, calculations have been performed using a Monte-Carlo code, together with data collected on the ISS. These calculations indicate that charged particles contribute <2% to the bubble count on the ISS, and can therefore be considered as negligible for bubble-detector measurements in space.

[Analysis of functional properties of biologically active substances using eukaryotic cell models (review)].

This work presents an analysis of current data on the investigation into the functional properties of biologically active substances in model systems based on cultivated human cells. The knowledge regarding the practical application of cell cultures for the analysis of functional properties of bioactive substances is summarized, including antioxidant, immunomodulating, pro- and prebiotics, and chemoprevention properties. The most promising directions in cell culture model development for the investigation of functional properties, including three-dimensional models, are discussed.

[Effect of Pro11-Ala11 amino acid substitution on structural and functional properties of antimicrobial peptide buforin 2].

Molecular dynamics simulations were used to investigate spatial structure of antimicrobial peptide buforin 2 in water and in toroidal transmembrane pores. It is shown that Pro11-Ala11 amino acid substitution contributes to stabilization of the helix and enables the peptide to form stable transmembrane toroidal pore. The results obtained correlate with the changes observed when modified buforin 2 interacts with cells.

[Comparisons of cerebral circulation parameters in schoolchildren living in the Far East and European North].

Transcranial Doppler sonography and impedansometry was used to study cerebral circulation in students aged from 7 to 17 living in the North in the "absolute discomfort" area (Magadan region. 62 degrees North, 158 degrees East, n = 167) and "discomfort" area (Arkhangelsk region, 61 degrees North, 41 degrees East, n = 52). New data were obtained about both blood flow parameters in main cerebral arteries, vessels tone and vasomotor reactivity as well as differences between these indices in children from the two northern areas. The results reveal that arterial blood flow velocity (BFV) in cerebral arteries is faster in Koryaks and Evens who are the children of the native population compared to BFV in the children born in the North whose parents represent newcomers. A tendency exists in the form of vascular tone rising in the living in the North students. This tendency is more expressed in children and adolescents from Magadan region which is distinguished from Arkhangelsk region by more severe climate. The indices that characterize individual alterations of cerebral circulation under hypoxic-cold factors as well as population peculiarities related to "polar adaptive type of metabolism" forming are discussed.

[Direct angioplasty of the left main coronary artery with a pericardium flap].

Surgical treatment of stenosis of the left main coronary artery (LMCA) is a special problem, a number of questions of surgical strategy for this lesion still remain unsolved. The question of direct plasty dilatation of LMCA has not lost its actuality. Operations were made on 6 patients in whom direct plasty dilatation of LMCA with a flap from autopericardium was performed for local, not lengthy constriction which was located in the initial and middle part of LMCA. The operations were made under conditions of extracorporeal circulation, moderate general hypothermia (about 32 degrees C), pharmacohypothermic cardioplagia with external cooling of the heart. In all cases there was good restoration of cardiac activity and the absence of myocardium ischemia at the postoperative period. The restoration of the anatomical lumen of LMCA by this method facilitated sufficient blood flow along LMCA. Five years later all the patients are alive, one patient has external angina of the 11 functional class.

[The structural and dynamic model of the serotonin 5-HT3 receptor. Comparative analysis of the structure of the channel domain of pentameric ligand-gated ion channels].

The three-dimensional structure of the 5-HT3 receptor is currently unknown. An available structure of the nicotinic acetylcholine receptor closely related by homology to the 5-HT3 receptor was used as a template for the computer-based homology modeling of the 5-HT3 receptor. The study of the ion migration through the channel by the stirred molecular dynamics method has shown that the steric factor in the region of residue THR 279 and the region of GLU 272, ASP 293 influences the ion transmission. The characteristic of the close interaction between the ion and the amino acid substitutions of the 5-HT3 channel was studied by computing the energy profile using constraint force molecular dynamic simulations. The amino acid sequence responsible for selective ion transmission has been investigated. The structure of the channel domain of the serotonin 5-HT3 receptor as a universal functional unit of the ligand-gated ion channels was discussed.

[Comparative studies of structural properties of melittin in water and trifluroethanol/water mixture by the molecular dynamics method].

The structural properties and dynamic behavior of the antimicrobial peptide melittin in hydrophobic and polar environments have been investigated. The main characteristics of the secondary structure of melittin in different media have been analyzed, and compared with the data on the ideal alpha-helix. It has been shown that melittin is an alpha-helix bent in the region of residue Pro14; in this case, the N-terminus of the peptide tends to unfold, while the C-terminal segment (residues 14-23) retains the helical structure for 20 ns of the simulation. 2,2,2-Trifluoroethanol molecules stabilize the helical structure of the peptide through lowering the dielectric constant of the environment and preferential accumulation nearby particular segments of the polypeptide chain.

[Molecular dynamics of zervamicin II and its analogues in water and methanol].

A comparative study of the molecular dynamics of zervamicin II (an antimicrobial peptide from the peptaibol group, which has the channel-forming activity) in water and methanol has been performed. The influence of amino acid substitutions on the dynamics and stability of the peptide structure has been investigated. The amino acid sequence responsible for the absence of swivel motions in short peptaibols has been determined.

[Enzymatic hydrolysis of keratin-containing stock for obtaining protein hydrolysates].

Optimization of the process of enzymatic hydrolysis of keratin-containing stock aimed at obtaining hydrolysates of high biological value has been performed. The increasing of the stock/water weight ratio, the amount of the alkaline protease preparation from Acremonium chrysogenium added and the temperature of the reaction mixture resulted in an increase in the yield and antioxidant capacity of hydrolysis products. The molecular masses of soluble products obtained under optimal hydrolysis conditions ranged from 3.55 to 3.60 kDa. High antioxidant capacity, 100% bioavailability and a well-balanced amino acid composition was characteristic of the hydrolysis products.

[Antioxidant and peroxidase activity of saliva in patients with inflammatory periodontal diseases and ability of their correction].

Comparative investigation of antioxidant and peroxidase activities of mixtured saliva during testing loads in control group, as well as in patients with caries and combination of caries with inflammatory periodontal diseases was carried out. Antioxidant activity of saliva in the last two groups was significantly lower, so their correction with xidiphone was made.