Halogen Bond-Involving Self-Assembly of Iodonium Carboxylates: Adding a Dimension to Supramolecular Architecture

We designed 0D, 1D, and 2D supramolecular assemblies made of diaryliodonium salts (functioning as double σ-hole donors) and carboxylates (as σ-hole acceptors). The association was based on two charge-supported halogen bonds (XB), which occurred between IIII sites of the iodonium cations and the carboxylate anions. The sequential introduction of the carboxylic groups in the aryl ring of the benzoic acid added a dimension to the 0D supramolecular organization of the benzoate, which furnished 1D-chained and 2D-layered structures when terephthalate and trimesate anions, correspondingly, were applied as XB acceptors. The structure-directing XB were studied using DFT calculations under periodic boundary conditions and were followed by the one-electron-potential analysis and the Bader atoms-in-molecules topological analysis of electron density. These theoretical methods confirmed the existence of the XB and verified the philicities of the interaction partners in the designed solid-state structures.

Influence of Extracellular Matrix Components on the Differentiation of Periodontal Ligament Stem Cells in Collagen I Hydrogel

Regeneration of periodontal tissues requires an integrated approach to the restoration of the periodontal ligament, cementum, and alveolar bone surrounding the teeth. Current strategies in endogenous regenerative dentistry widely use biomaterials, in particular the decellularized extracellular matrix (dECM), to facilitate the recruitment of populations of resident cells into damaged tissues and stimulate their proliferation and differentiation. The purpose of our study was to evaluate the effect of the exogenous components of the extracellular matrix (hyaluronic acid, laminin, fibronectin) on the differentiation of periodontal ligament stem cells (PDLSCs) cultured with dECM (combinations of decellularized tooth matrices and periodontal ligament) in a 3D collagen I hydrogel. The immunohistochemical expression of various markers in PDLSCs was assessed quantitatively and semi-quantitatively on paraffin sections. The results showed that PDLSCs cultured under these conditions for 14 days exhibited phenotypic characteristics consistent with osteoblast-like and odontoblast-like cells. This potential has been demonstrated by the expression of osteogenic differentiation markers (OC, OPN, ALP) and odontogenic markers (DSPP). This phenomenon corresponds to the in vivo state of the periodontal ligament, in which cells at the interface between bone and cementum tend to differentiate into osteoblasts or cementoblasts. The addition of fibronectin to the dECM most effectively induces the differentiation of PDLSCs into osteoblast-like and odontoblast-like cells under 3D culture conditions. Therefore, this bioengineered construct has a high potential for future use in periodontal tissue regeneration.

Endogenous Regeneration of Alveolar Bone by Decellularized Tooth Matrix

The efficiency of bone tissue regeneration by decellularized tooth matrix, demineralized tooth matrix, and commercial xenograft Bio-Oss Spongiosa was compared on the model of a critical-size circular defect in the alveolar bone of the upper jaw of adult Wistar rats. The defect healing dynamics was assessed using histological, histomorphometrical, and immunohistochemical methods on days 30 and 60. In contrast to demineralized matrix and commercial xenograft, decellularized matrix induces the formation of the new bone tissue by day 60. Decellularized matrix can be considered as a biomaterial for cell-free tissue engineering for alveolar bone restoration in dentistry and maxillofacial surgery.

Identification of Chimeric NTRK3 Genes in Papillary Thyroid Cancer Cells by Analyzing the Imbalance of the Expression of 5' and 3' mRNA Fragments

The standard for detecting chimeric genes of neurotrophic receptor tyrosine kinases (NTRK) is next generation sequencing (NGS). However, this analysis is expensive and takes several days. As a rapid screening method for the detection of NTRK3-dependent papillary thyroid cancer, an analysis of the expression imbalance between 5' and 3' NTRK3 mRNA fragments was used (5'/3' RT-PCR). The reference method for detection of NTRK3 rearrangements was fluorescent in situ hybridization (FISH), and the most frequent rearrangements in papillary thyroid cancer were tested using reverse transcription PCR (RT-PCR). Using 5'/3' RT-PCR, 18 samples of papillary thyroid cancer carrying chimeric transcripts of NTRK3 mRNA were detected. The sensitivity of the developed technique was 88.9% and specificity was 99.3%. Thus, a fast and cost-effective method of screening samples of papillary thyroid cancer in paraffin blocks is proposed with acceptable sensitivity and specificity.

Differences in Transcriptomic Profiles of Brain and Thyroid Tumors with NTRK Gene Rearrangement

For tumors with chimeric NTRK genes, entrectinib and larotrectinib can be prescribed regardless of tumor localization. We compared changes in the transcriptional activity of genes in brain tumors (BT) and thyroid cancer (TC) with rearrangement (NTRK+) and without rearrangement (NTRK-) of the NTRK genes using The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. We revealed an increase in the transcription of the JUN gene in NTRK+ samples in comparison with NTRK- samples: by 1.6 times for BT (p=0.239) and by 2.5 times for TC (p=0.003). The transcription of eight HOX genes in NTRK+ BT samples was also increased (by 85-725 times, p<0.05) in comparison with NTRK-. In NTRK+ TC samples, the level of miR-31 and miR-542 was statistically significantly higher (by 3 and 2.5 times, respectively) than in NTRK-samples. For the NTRK+ BT samples, the levels of miR-10b, miR-182, and miR-21 more than 5-fold surpassed the corresponding values in NTRK-samples (p<0.05). These findings reflect differences in activation of gene transcription resulting from NTRK gene rearrangement in BT and TC.

Histological Variants of Papillary Thyroid Cancer in Relation to Clinical and Morphological Parameters and Prognosis

The correlation of histological features of papillary thyroid cancer with clinical and morphological prognostic factors and cause-specific mortality was analyzed in a case-control study within a cohort of patients from the Altai Regional Oncology Center (25 cases with lethal outcome and 64 follow-up controls). Significant variability was revealed in the histological structure of papillary thyroid cancer with the prevalence of classic (62%) and less frequent follicular (19%), tall cell (8%), and solid (7%) variants. In comparison with the classic variant, the solid variant was more often associated with male sex and large tumor size; follicular and tall cell variant was associated with more frequent metastases to regional lymph nodes; follicular and solid variants were associated with an increased proportion of cases with disease stages III-IV. The main differences reflecting the effect of histological factor on the disease outcome were associated with the solid variant of papillary thyroid cancer that was detected in 21% of lethal cases and only in 2% of control subjects. The detection of this variant can be of importance as an additional prognostic factor of the postoperative survival in papillary thyroid cancer.

DNA Damage in Splenocytes of Mice Exposed to Secondary Radiation Created by 650 MeV Protons Bombarding a Concrete Shielding Barrier

The proportion of splenocytes with a high level of DNA double-strand breaks was determined in mice exposed to primary and secondary radiation created by bombarding of a concrete barrier (thickness 20, 40, and 80 cm) by 650 MeV protons. The proportion of splenocytes with a high level of DNA double-strand breaks was assessed by flow cytometric analysis of γH2AX⁺ and TUNEL⁺ cells. It is shown that concrete barrier can significantly reduce primary proton radiation; the severity of negative biological effects in mice irradiated in the center of the proton beam decreased with increasing the thickness of this barrier. However, the spectrum of secondary radiation changes significantly with increasing the barrier thickness from 20 to 80 cm and the distance from central axis of the beam from 0 to 20 cm, and the proportion of the neutron component increases, which also causes negative biological effects manifesting in a significant (p<0.05) increase in the percentage of splenocytes with a high level of DNA damage in mice irradiated at a distance of 20 cm from the center of the proton beam and receiving relatively low doses (0.10-0.17 Gy).

Electrospun Magnetic Composite Poly-3-hydroxybutyrate/Magnetite Scaffolds for Biomedical Applications: Composition, Structure, Magnetic Properties, and Biological Performance

Magnetically responsive composite polymer scaffolds have good potential for a variety of biomedical applications. In this work, electrospun composite scaffolds made of polyhydroxybutyrate (PHB) and magnetite (Fe₃O₄) particles (MPs) were studied before and after degradation in either PBS or a lipase solution. MPs of different sizes with high saturation magnetization were synthesized by the coprecipitation method followed by coating with citric acid (CA). Nanosized MPs were prone to magnetite-maghemite phase transformation during scaffold fabrication, as revealed by Raman spectroscopy; however, for CA-functionalized nanoparticles, the main phase was found to be magnetite, with some traces of maghemite. Submicron MPs were resistant to the magnetite-maghemite phase transformation. MPs did not significantly affect the morphology and diameter of PHB fibers. The scaffolds containing CA-coated MPs lost 0.3 or 0.2% of mass in the lipase solution and PBS, respectively, whereas scaffolds doped with unmodified MPs showed no mass changes after 1 month of incubation in either medium. In all electrospun scaffolds, no alterations of the fiber morphology were observed. Possible mechanisms of the crystalline-lamellar-structure changes in hybrid PHB/Fe₃O₄ scaffolds during hydrolytic and enzymatic degradation are proposed. It was revealed that particle size and particle surface functionalization affect the mechanical properties of the hybrid scaffolds. The addition of unmodified MPs increased scaffolds' ultimate strength but reduced elongation at break after the biodegradation, whereas simultaneous increases in both parameters were observed for composite scaffolds doped with CA-coated MPs. The highest saturation magnetization─higher than that published in the literature─was registered for composite PHB scaffolds doped with submicron MPs. All PHB scaffolds proved to be biocompatible, and the ones doped with nanosized MPs yielded faster proliferation of rat mesenchymal stem cells. In addition, all electrospun scaffolds were able to support angiogenesis in vivo at 30 days after implantation in Wistar rats.

Solidification of ternary melts with a two-phase layer

This review is concerned with the nonstationary solidification of three-component systems in the presence of two moving phase transition regions-the main (primary) and cotectic layers. A non-linear moving boundary problem has been developed and its analytical solutions have been defined. Namely, the temperature and impurity concentration distributions were determined, the solid phase fractions in the phase transition regions and the laws of motion of their boundaries were found. It was shown that variations in the initial impurity concentration affect significantly the ratio between the lengths of the two-phase layers. A non-linear liquidus surface equation is theoretically taken into account as well.

Prediction of EVT6-NTRK3-Dependent Papillary Thyroid Cancer Using Minor Expression Profile

Solid tumors resulting from oncogenic stimulation of neurotrophin receptors (TRK) by chimeric proteins are a group of rare tumors of various localization that respond to therapy with targeted drugs entrectinib and larotrectinib. The standard method for detecting chimeric TRK genes in tumor samples today is considered to be next generation sequencing with the determination of the prime structure of the chimeric transcripts. We hypothesized that expression of the chimeric tyrosine kinase proteins in tumors can determine the specific transcriptomic profile of tumor cells. We detected differentially expressed genes allowing distinguishing between TRK-dependent tumors papillary thyroid cancer (TC) from other molecular variants of tumors of this type. Using PCR with reverse transcription (RT-PCR), we identified 7 samples of papillary TC carrying a EVT6-NTRK3 rearrangement (7/215, 3.26%). Using machine learning and the data extracted from TCGA, we developed of a recognition function for predicting the presence of rearrangement in NTRK genes based on the expression of 10 key genes: AUTS2, DTNA, ERBB4, HDAC1, IGF1, KDR, NTRK1, PASK, PPP2R5B, and PRSS1. The recognition function was used to analyze the expression data of the above genes in 7 TRK-dependent and 10 TRK-independent thyroid tumors obtained by RT-PCR. On the test samples from TCGA, the sensitivity was 72.7%, the specificity - 99.6%. On our independent validation samples tested by RT-PCR, sensitivity was 100%, specificity - 70%. We proposed an mRNA profile of ten genes that can classify TC in relation to the presence of driver NTRK-chimeric TRK genes with acceptable sensitivity and specificity.

[Is there a claudin-low phenotype of breast cancer?]

The novel molecular subtype of breast cancer (BC), named "claudin-low", was described in 2007. It was characterized by the consistently low expression of genes involved in the formation of epithelial tight junctions in combination with the high activation of genes associated with the epithelial-to-mesenchymal transition, as well as tumor stem cell markers. The similar claudin- low subtype was later identified at the transcriptional level in bladder cancer, gastric cancer, and serous ovarian cancer. However, only in relation to BC, attempts were made to create a surrogate panel for immunohistochemical identification of this subtype in a manner like the intrinsic molecular BC subtypes identified using three main markers, such as ER, PR, and HER-2. At the same time, the ambiguity in the expression of claudins among the subtypes of BC, which is defined by various authors at the immunohistochemical level, as well as the absence of both the confirmed set of immunohistochemical criteria and a unified approach to their assessment, complicate these efforts. The purpose of the review is to show that the immunohistochemical identification of claudin-low subtype of BC is a separate problem that has significant limitations, needs standardization and has not yet reached diagnostic value.

[Epithelial-stromal interactions in pancreatic adenocarcinoma: the role of stroma in disease progression]

Pancreatic ductal adenocarcinoma (PDAC) is the most common and difficult to treat form of pancreas cancer. PDAC and other solid cancers contain both tumor cells and normal connective tissue cells called stromal cells, which are responsible for the excess production of extracellular matrix. It is known that in more than 90% of PDAC tumors and in many other types of cancer, mutations of the KRAS gene are observed, the reciprocal signaling of which has been shown between tumor and stromal cells in vitro. Pancreatic stromal stellate cells are considered precursors of activated or tumor-associated fibroblasts (CAFs), which are an increasing population of cells that proliferate in situ or are recruited into the tumor. CAFs are a heterogeneous population of stromal fibroblasts with different molecular profiles that change during tumorigenesis. Both immunosuppressive and immunosuppressive subsets of CAFs can coexist in the stroma of a single tumor. Based on the heterogeneity of the intertumor stroma, attempts are being made to classify PDAC and predict the course of the disease.

Modern Approaches to Acellular Therapy in Bone and Dental Regeneration

An approach called cell-free therapy has rapidly developed in regenerative medicine over the past decade. Understanding the molecular mechanisms and signaling pathways involved in the internal potential of tissue repair inspires the development of new strategies aimed at controlling and enhancing these processes during regeneration. The use of stem cell mobilization, or homing for regeneration based on endogenous healing mechanisms, prompted a new concept in regenerative medicine: endogenous regenerative medicine. The application of cell-free therapeutic agents leading to the recruitment/homing of endogenous stem cells has advantages in overcoming the limitations and risks associated with cell therapy. In this review, we discuss the potential of cell-free products such as the decellularized extracellular matrix, growth factors, extracellular vesicles and miRNAs in endogenous bone and dental regeneration.

[The first experience of endovascular treatment of chronic subdural hematomas with non-adhesive embolization materials of various viscosities: Squid 12 and 18]

Chronic subdural hematomas (CSH) usually require surgical evacuation via a burr hole or craniotomy. Certain incidence of recurrent postoperative CSH is known. Middle meningeal artery (MMA) embolization has been described as an alternative surgery for new or recurrent CSH or as a preventive measure to reduce the risk of postoperative recurrence. The authors report successful MMA embolization with 2 non-adhesive embolic agents of various viscosities (SQUID 12 and SQUID 18, Balt USA, Irvine, CA, USA) for recurrent postoperative CSH in a 44-year-old woman.

Rat Blood Leukocytes after Intravenous Injection of Magnetoliposomes on the Basis of Nanomagnetite

The structure of blood neutrophils, eosinophils, monocytes, and lymphocytes and differential white blood count in adult rats were studied over 120 days after a single intravenous injection of magnetoliposomes based on nanomagnetite. Magnetoliposomes had no effect on the structure of neutrophils, eosinophils, monocytes, and lymphocytes. At the same time, injection of a suspension of magnetoliposomes based on magnetite nanoparticles led to a decrease in lymphocyte count and an increase in the count of monocytes and band and segmented neutrophils in the blood. These changes were transient and the parameters returned to normal by day 40-60 after injection.

Single-beam multimodal nonlinear-optical imaging of structurally complex events in cell-cycle dynamics

We demonstrate a multimodal nonlinear-optical imaging that combines second- and third-harmonic generation (SHG and THG) with three-photon-excited fluorescence (3PEF) as a means to resolve fine details of the cell structure and trace its transformations throughout structurally complex episodes of cell-cycle dynamics, including the key stages and signatures in cell division. When zoomed in on cell mitosis, this technique enables a high-contrast multimodal imaging of intra- and extracellular signatures of cell division, detecting, via a multiplex, 3PEF/SHG/THG readout, a remarkable diversity of shapes, sizes, and symmetries in a truly single-beam setting, with no need for beam refocusing or field-waveform re-adjustment.

Multimodal nonlinear-optical imaging of nucleoli

Multimodal nonlinear microscopy combining third-harmonic generation (THG) with two- and three-photon-excited fluorescence (2PEF and 3PEF) is shown to provide a powerful resource for high-fidelity imaging of nucleoli and nucleolar proteins. We demonstrate that, with a suitably tailored genetically encoded fluorescent stain, the 2PEF/3PEF readout from specific nucleolar proteins can be reliably detected against the extranucleolar 2PEF/3PEF signal, enabling high-contrast imaging of the key nucleolar ribosome biogenesis components, such as fibrillarin. THG is shown to provide a versatile readout for unstained nucleolus imaging in a vast class of biological systems as different as neurons in brain slices and cultured HeLa cells.

Claudins as biomarkers of differential diagnosis and prognosis of tumors

Claudins are a superfamily of transmembrane proteins, the optimal expression and localization of which are important for the normal physiological function of the epithelium and any imbalance may have pathological consequences. Not only insufficient but also excessive production of claudins in cancer cells, as well as their aberrant localization, equally manifest the formation of a malignant phenotype. Many works are distinguished by contradictory data, which demonstrate the action of the same claudins both in the role of tumor-growth suppressors and promoters in the same cancers. The most important possible causes of significant discrepancies in the results of the works are a considerable variability of sampling and the absence of a consistent approach both to the assessment of the immune reactivity of claudins and to the differential analysis of their subcellular localization. Combined, these drawbacks hinder the histological assessment of the link between claudins and tumor progression. In particular, ambiguous expression of claudins in breast cancer subtypes, revealed by various authors in immunohistochemical analysis, not only fails to facilitate the identification of the claudin-low molecular subtype but rather complicates these efforts. Research into the role of claudins in carcinogenesis has undoubtedly confirmed the potential value of this class of proteins as significant biomarkers in some cancer types; however, the immunohistochemical approach to the assessment of claudins still has limitations, needs standardization, and, to date, has not reached a diagnostic or a prognostic value.

[Endovascular treatment of extracranial dissecting aneurysms of cervical arteries]

BACKGROUND

Dissecting aneurysms of extracranial cervical arteries are a rare vascular pathology. To date, there is no consensus on the choice of optimal surgical approach for these aneurysms.

OBJECTIVE

To evaluate the effectiveness of endovascular treatment of various extracranial dissecting aneurysms.

MATERIAL AND METHODS

There were 19 patients with 21 extracranial dissecting aneurysms for the period from January 1, 2013 to October 19, 2020. Clinical examination, ultrasound and neuroimaging data were considered to determine surgical intervention.

RESULTS

Nineteen patients underwent 20 intravascular interventions: aneurysm embolization with detachable coils with stent-assistance (n=9), flow-diverting stent implantation (n=5), arterial reconstruction with a stent for carotid stenting (n=3), aneurysm embolization with balloon assistance (n=1), aneurysm embolization with detachable coils without assistance (n=2). There were no complications. All patients were discharged without neurological impairment after 1-5 days. Long-term results of control angiography were analyzed within 1-19 months in 12 patients. All aneurysms were completely occluded. Asymptomatic occlusion of flow-diverting stent together with aneurysm occurred in 1 patient with low compliance to antiplatelet therapy. Other 6 patients are scheduled for elective angiography.

CONCLUSION

Extracranial dissecting aneurysms of cervical arteries require vigilance due to their rare occurrence and risk of severe complications. In our opinion, intravascular interventions are advisable for these patients as effective and safe procedures.

Osteogenic Potential of Decellularized Tooth Matrix

We studied the possibility of using decellularized tooth matrix as a scaffold to restore bone tissue. It was found that mesenchymal stem cells underwent spontaneous osteogenic differentiation on the decellularized tooth matrix, which makes it possible to use it as a natural allograft in the treatment of resorption of alveolar bone tissue.

Behavioral Responses and Immune and Cytogenetic Parameters of Food-Restricted Mice

The experiments on mice showed that subchronic food restriction to 40 and 8% of unrestricted ration is a strong stressor inducing devastation of lymphoid organs, primarily the thymus and spleen. The mice in the group with severe food restriction (8% of normal ration) demonstrated increased front paw grip force. We also observed an increase in spontaneous motor activity in these animals correlated with food restriction. Food deprivation led to inhibition of proliferative activity of the bone marrow cells and suppression of erythropoiesis. Moreover, severe food restriction was accompanied by a decrease in the number of double-strand DNA breaks evaluated by the release of γH2AX⁺-cells and the ratio of polychromatophilic erythrocytes.

Cell-specific three-photon-fluorescence brain imaging: neurons, astrocytes, and gliovascular interfaces

We present brain imaging experiments on rat cortical areas, demonstrating that, when combined with a suitable high-brightness, cell-specific genetically encoded fluorescent marker, three-photon-excited fluorescence (3PEF), enables subcellular-resolution, cell-specific 3D brain imaging that is fully compatible and readily integrable with other nonlinear-optical imaging modalities, including two-photon-fluorescence and harmonic-generation microscopy. With laser excitation provided by sub-100-fs, 1.25-µm laser pulses, cell-specific 3PEF from astrocytes and their processes detected in parallel with a three-photon-resonance-enhanced third harmonic from blood vessels is shown to enable a high-contrast 3D imaging of gliovascular interfaces.

Update of ion-optical system of neutral beam of Tokamak à Configuration Variable

An injector of fast deuterium atoms for plasma heating was designed and installed at the Tokamak à Configuration Variable (TCV). The neutral beam can deliver 1 MW power to the plasma in 2 s pulses. An ion beam of the injector is formed by a triode multislit ion-optical system with spherical electrodes which provide ballistic focusing. Tests at TCV revealed that the total angular divergence of the neutral beam across the slits exceeded the expected value more than twice. It was finally established that this increase in divergence was caused by the asymmetry of the chamfers at the slit edges of the plasma electrode. The redesigned shape of the slits of the plasma grid together with precise machining significantly improved the beam quality. Experimental testing proved that the neutral beam profile in the direction across the grid slits became very close to the expected value.

[Dimeric bisbenzimidazoles suppress the herpes simplex virus and human cytomegalovirus infections in cell сultures]

Antiviral activity of new AТ-specific fluorescent symmetric dimeric bisbenzimidazoles of DBА(n) series was assessed in the cell models of infections caused by type 1 herpes simplex virus (HSV1) and human cytomegalovirus (CMV). In DBA(n) molecules bisbenzimidazole fragments are bound to an oligomethylene liner with varied number of methylene groups in the linker (n = 1, 3, 5, 7, 9, 11). In contrast to DB(n) dimeric bisbenzimidazoles, in DBA(n) series terminal fragments of macromolecules contain N-dimethylaminopropylcarboxamide groups instead of N-methylpiperazine groups. DBА(n) compounds better dissolve in water, pass across plasma and nuclear membrane, and stain DNA in living cells. DBA(1) and DBA(7) produced therapeutic effects in HSV1 infection; DBA(7) completely suppressed the infection. DBA(11) displayed in vitro therapeutic activity in HSV1 and CMV infections. In addition, DBA(7) and DBA(1) showed microbicidal activity. Thus, DBA(11), which is active against two viruses causing severe diseases with serious health consequences for immunodeficient individuals, should be further investigated. High antiviral activity of DBA(7) in all test models indicates that this compound is a promising active agent for innovative antiviral drugs.

Peculiarities of Osteogenesis by Periosteal Cells after Experimental Ectopic Transplantation

We carried out a comparative study of the features of osteogenesis from the progenitor osteogenic periosteal cells in rabbit and human. At the initial stages, high osteogenic potential of both human and rabbit periosteal cells was observed. However, at the later stages, the cell response favors resorption of the new bone tissue formed from periosteal cells in rabbits, but does not affect the bone tissue formed from human progenitor osteogenic periosteal cells. These functional characteristics of rabbit periosteal cells should be considered when planning the experiment.

[Role of tenascin С in triple-negative breast cancer]

AIM

to establish a relationship between the main markers tumor stem cells (TSCs), CD44, and CD24, the level of tenascin C production, and chemoresistance in triple-negative breast cancer (BC).

SUBJECTS AND METHODS

Thirty biopsy specimens from triple-negative BC patients who had conventionally received preoperative chemotherapy followed by surgery were selected in the investigation. All the selected patients were conventionally assigned to neoadjuvant polychemotherapy (PCT) with paclitaxel and carboplatin. The surgical specimens were analyzed in relation to the degree of a tumor morphological response to PCT. The magnitude of the health-promoting effect of neoadjuvant therapy was evaluated according to the residual cancer burden (RCB) system using an on-line calculator; RCB was categorized into classes (from RCB-0 to RCB-III). The markers CD44, СD24, and tenascin C were identified by the standard immunoperoxidase method in the primary biopsies.

RESULTS

Varying morphological responses of triple-negative breast cancer to PCT were revealed, which showed resistance in 60% of the cases. The chemoresistance found in most (87%) cases coincided with the identification of the CD44+/CD24low/- profile. The detection of the higher production of the extracellular matrix tenascin C participating in the formation of the TSC niche fully combined with the CD44+/CD24low/- phenotype; while the maximum response to tenascin C was noted in the cases differing in not only a lack of responses to PCTs, but also in the most aggressive course in conjunction with metastatic disease.

CONCLUSION

Immunohistochemical analysis shows that the unique association between the CD44+/CD24low/- phenotype and the pronounced production of tenascin C may have a prognostic potential, prospectively indicating the inefficiency of neoadjuvant PCT, in particular that with platinum derivatives, which is used for the standard treatment of triple-negative BC. Taking into account the role of tenascin C in invasion, metastasis, and chemoresistance, it per se may be considered as a promising target for the targeted and/or combined therapy of triple-negative BC.

[Extrapontine myelinolysis developed after aneurysmal subarachnoid hemorrhage (a case report and literature review)]

TOPICALITY

Central pontine and extrapontine myelinolysis is a rare and dangerous form of the demyelinating process of undefined origin, the development of which is associated with a very low sodium level in the blood (hypernatremia).

OBJECTIVE

To describe a rare case of extrapontine myelinolysis as a complication occurring in the hemorrhagic period of anterior communicating artery aneurysm rupture as well as to demonstrate that this condition can be diagnosed intravitally.

CONCLUSION

Clinical vigilance of extrapontine myelinolysis may promote the timely diagnosis and treatment of this disease, which is a potential cause of death. Pulse-therapy with glucocorticoids provides the opportunity to achieve regression of neurological symptoms and to stabilize the patient's condition.

[The highly specific and sensitive analysis of repertoire of serum antibodies using peptide microchips in patients with diagnosis of breast cancer.]

Nowadays, the search for new biomarkers of cancer is actual for early diagnostic. The antibodies against antigens associated with tumors arouse an interest as an alternative to the present biomarkers. The alteration of quantity and specificity of antibodies in blood serum indicates processes occurring in the organism, including development of oncologic diseases. The article presents the results of analysis of repertoire of antibodies (immunosignatures) using peptide micro-chips in patients with diagnosis of breast cancer. The study established 119 informative peptides out of 330 034 peptides, presented on the microchip. The binding of antibodies with them demonstrates statistically significant intergroup values (p<0.001). This panel of peptides is effective in discerning sera of patients and healthy donors with high sensitivity and specificity. The evaluation of repertoire of antibodies interacting with panel of synthetic peptides can be used in development of diagnostic tests in case of detection of breast cancer at early stages.

[STUDYING GASTRIC ULCERATION EFFECT OF A NEW DRUG INTENDED FOR TREATMENT OF CHRONIC INFLAMMATORY DISEASES OF KIDNEYS AND URINARY TRACT.]

Gastric ulceration properties (gastrointestinal toxicity) of the sodium salt of 4-(0-β-D-glucopyranosyloxy) benzoic acid, a new nonsteroidal anti-inflammatory drug (NSAID) intended for the treatment of chronic inflammatory diseases of the kidney and urinary tract, have been tested on laboratory animals. Acute NSAID-induced gastropathy was induced in rats by oral administration of indomethacin, nimesulide, diclofenac, acetylsalicylic acid and the new drug. Test animals were killed by instantaneous decapitation 4 h after treatment and their gastrointestinal tracts were studied by pathomorphological methods on micropreparations and histological sections of gastric mucosa. It was established that the new drug, in contrast to reference NSAIDS, did not exhibit gastropathic action on the gastric mucosa.

ANTI-INFLAMMATORY ACTIVITY OF SODIUM SALT OF 4-(O-β-D-GLUCOPYRANOSYLOXY)BENZOIC ACID

We have evaluated the anti-inflammatory activity of the sodium salt of 4-(O-β-D-glucopyranosyloxy)benzoic acid in comparison to well-known nonsteroidal anti-inflammatory drugs (NSAIDs). Carrageenan suspension (1%, 0.1 mL) was injected into subplantar region of the right hindpaw of rats (n = 12) pretreated (7 days and 60 min before carrageenan injection) intragastrically with methyl ester of 4(β-D-glucopyranosyloxy)benzoic acid (20 mg/kg), acetylsalicylic acid (20 mg/kg), 4-hydroxybenzoic acid (20 mg/kg), or vehicle (2 mL of purified water). Paw edema volume was measured plethysmographically at 1, 2 and 4 h after carrageenan injection. The results showed that intragastric administration of the sodium salt of 4-(O-β-D-glucopyranosyloxy)benzoic acid in a dose of 20 mg/kg for 7 days decreased the intensity of experimental inflammation.

Early Response of Mouse Bone Mrrow Cells to Short-Term Irradiation in a Wide Range of Doses

Experiments on mice irradiated with γ-rays in a wide range of doses, from 0.5 to 400 cGy and the bone marrow have shown cytogenetic and cytological effects ranging from I cGy dose 24 hours after exposure to radiation. Dose-independent reduction of the number of nucleated cells in the bone marrow, normal or even elevated levels of mitotic activity, and extreme dependence of the type of chromosomal aberrations on the radiation dose with the maximum in the region of 7.5 cGy were observed in the dose range from 1 to 20 cGy. A linear dose-dependent decrease of the cell.number in the bone marrow, a decreased mitotic activity and increased number of aberrant mitosis were marked in the dose range from 20 to 400 cGy. The findings are discussed in terms of their application for explaining the mechanisms of hormesis, adaptive response, as well as the appropriateness of accounting the parameters studied for solving problems of regulation of permissible doses.

Waves of c-Fos and Arc Proteins Expression in Neuronal Populations of the Hippocampus in Response to a Single Episode of New Experience

Accumulation of c-Fos and Arc proteins in neurons in different regions of the hippocampus after single trial of contextual fear conditioning was studied by using immunohistochemical staining. We found that the dynamics of the c-Fos and Arc expression has a biphasic pattern: the first peak was observed in 15-30 min after learning and the second less pronounced peak in 1-3 h. Induction of Arc occurred earlier than c-Fos and the overall dynamics of the two waves slightly varied in the dentate gyrus and hippocampal CA1 and CA3 fields. The findings open the possibility of mapping the cognitive neural networks of the brain with higher temporal resolution and draw attention to fluctuations of hippocampal activity after a single brief episode of new experience.

Note: Arc discharge plasma source with plane segmented LaB6 cathode

A plane cathode composed of close-packed hexagonal LaB6 (lanthanum hexaboride) segments is described. The 6 cm diameter circular cathode is heated by radiation from a graphite foil flat spiral. The cathode along with a hollow copper anode is used for the arc discharge plasma production in a newly developed linear plasma device. A separately powered coil located around the anode is used to change the magnetic field strength and geometry in the anode region. Different discharge regimes were realized using this coil.

[Tumor stem cells in breast cancer]

High mortality from breast cancer is associated with the high heterogeneity of tumor and the frequent recurrences of the pathological process, which are due to the presence of tumor stem cells. The review considers the biological properties of tumor stem cells, the molecular mechanisms of their regulation, interaction with the microenvironment, and their role in the heterogeneity of the morphological and clinical forms of breast cancer.

[Modern problems and main ways of imorovement of disinfecting art in Armed Forces]

The article states the reasons defining the high relevance and significance of disinfection measures in modern conditions, reports general and specific problems of ensuring disinfection during medical service day-to-day activities. The directions of development of chemical and technical disinfectants and methods for'their use on different objects and under various climatic conditions are determined. It was shown that the crucial condition for implementation of theoretical and practical ways of improving disinfection affairs is a comprehensive approach based on concerted efforts of all authorities of Russian Armed Forces Medical Services, research and sanitary-epidemiological institutions, as well as relevant chars of the Military Medical Academy in close cooperation with representatives of domestic industry.

[CYTOGENETIC EFFECTS IN MICE BONE MARROW AFTER IRRADIATION BY FAST NEUTRONS]

Mechanisms of damaging mice bone marrow cells by 1.5 MeV neutrons at the dose of 25-250 cGy, dose rate of 23.9 cGy/s and γ-quants ⁶⁰Co as a standard radiation were studied. The mitotic index and aberrant mitoses in marrow preparations were counted in 24 and 72 hours after irradiation. Coefficients of relative biological effectiveness (RBE) of fast neutrons 24 and 72 hours post irradiation calculated from mitotic index reduction and aberrant mitoses formation were within the range from 4.1 ± 0.1 to 7.3 ± 0.1. Mean time of the existence of chromosomal aberrations in marrow cells was determined. For the specified doses from γ-rays, the period of aberrations existence was 1.4-1.1 cycles and for neutrons, 1.0-0.6 cycles. Morphologic analysis of neutron-induced damages and ratio of the most common breaks demonstrated a high production of bridges, which outnumbered cells with fragments in 3 to 4 times suggesting a more destructive effect on the genetic structures of cells. RBE of fast neutrons is a variable that grows with a radiation dose. Moreover, RBE estimated after 72 hours exceeded values it had 24 hours after irradiation.

[DIURETIC ACTIVITY OF 4-O-CARBOXYPHENYL-D-GLUCOPYRANOSIDE SODIUM SALT ADMINISTERED VIA DIFFERENT ROUTES]

It was compared the diuretic activity of the sodium salt of 4-(O-β-D-glucopyranosyloxy)benzoic acid for enteral (intragastric) and parenteral ways of administration. The test substance was administered enterally and parenterally (subcutaneously in the region of the withers) in a daily dose of 18 µmol/kg for the first seven days and in a dose of 54 mmol/kg for the next seven days. Diuretic activity of the sodium salt of 4-(O-β-D-glucopyranosyloxy)benzoic acid was evaluated in terms of urine volume. Urine was analyzed for creatinine and the concentration of sodium, potassium and chloride ions. Experiments showed that the sodium salt of 4-(O-β-D-glucopyranosyloxy)benzoic acid produced a diuretic effect only for the enteral administration route.

Progress in Mirror-Based Fusion Neutron Source Development

The Budker Institute of Nuclear Physics in worldwide collaboration has developed a project of a 14 MeV neutron source for fusion material studies and other applications. The projected neutron source of the plasma type is based on the gas dynamic trap (GDT), which is a special magnetic mirror system for plasma confinement. Essential progress in plasma parameters has been achieved in recent experiments at the GDT facility in the Budker Institute, which is a hydrogen (deuterium) prototype of the source. Stable confinement of hot-ion plasmas with the relative pressure exceeding 0.5 was demonstrated. The electron temperature was increased up to 0.9 keV in the regime with additional electron cyclotron resonance heating (ECRH) of a moderate power. These parameters are the record for axisymmetric open mirror traps. These achievements elevate the projects of a GDT-based neutron source on a higher level of competitive ability and make it possible to construct a source with parameters suitable for materials testing today. The paper presents the progress in experimental studies and numerical simulations of the mirror-based fusion neutron source and its possible applications including a fusion material test facility and a fusion-fission hybrid system.

[Use of diagnostic templates at stages of prosthetics treatment with implant-retained restorations]

The comparative analysis of efficiency of various types of diagnostic templates for planning orthopedic treatment of 50 patients with partial or complete absence of teeth was performed. The patients were divided in 3 groups according to template manufacturing technique. All diagnostic templates made in accordance with clinical conditions allowed transfering digital data of the scheduled prosthetic construction for virtual implantation planning. Advantages and pitfalls of each template type are discussed.

[SEARCHING FOR NEW SYNTHETIC DIURETICS]

This study was aimed at estimation of the diuretic and saluretic activity of 4-nitrophenyl-O-β-D-glucopyranoside and its aglicon 4-nitrophenol in rats. Test animals daily received 4-nitrophenyl-O-β-D-glucopyranoside (group 1) and 4-nitrophenol (group 2) intragastrically in 2 mL of distilled water in a dose of 18 µmol/kg from 1st to 7th day and 54 µmol/kg from 8th to 14th days. During the experiment, the most pronounced diuretic activity was observed for 4-nitrophenyl-O-β-D-glucopyranoside in a dose of 54 µmol/kg, which increased the diuresis in rats 2.5 times as compared to the control value.

[Cytogenetic investigations of bone marrow cells from mice exposed onboard biosatellite "Bion-M1"]

The results of studying the mitotic activities and chromosomal aberrations in bone marrow cells from C57/BL6N mice with the help of the anaphase technique in 12 hours after completion of the 30-day "Bion-M1" mission and ground-based experiment using flight equipment are presented. A statistically reliable decline of the mitotic activity (0.74%) was found in cells taken from the space flown animals. In the ground-based experiment, a statistically reliable downward trend in proliferative activity (1.37%) was revealed after the comparison with groups of vivarium control (1.46-1.53%). In both experiments mice increased the number of initial mitotic phases (prophase + metaphase) relative to the sum of anaphases and telophases. The number of aberrant mitoses grew reliably in the group of flight animals by 29.7%, whereas in the ground-based experiment an upward trend was insignificant as their number increased up to 2.3% only. In the vivarium controls aberrant mitoses constituted 1.75-1.8%. An increase in chromosomal aberrations was largely due to such abnormalities as fragments. These findings seem to have been a result of summation of the effects of radiation and other stressful factors in space flight.

[ZINK IS ACTIVATOR OF ENTERAL CALCIUM METABOLISM]

Experiments on goats and rabbits showed that zinc supplement to the diet leads to calcium concentration rise in muscle, bone and blood of animals. However, this rise was not adequate to increase in.zinc consumption. The bulk of alimentary zinc stayed in soluble fraction, dense endogen fraction and infusoria fraction of digesta and stimulated calcium release from food particles, it's accumulation in digesta fractions and calcium utilization on the whole. Authors estimate animal digesta as homeostatic, spatial organized, endogenic formation in which zinc and calcium are functionally dependent through enteral mucosa.

[CYSTEAMINE-INDUCED MODIFICATION OF CYTOGENETIC DAMAGES TO THE CORNEAL EPITHELIUM OF MICE EXPOSED TO CORPUSCULAR RADIATION WITH VARYING LINEAR TRANSFER ENERGIES]

Cytogenetic damages to cells of the corneal epithelium were studied in mice exposed to protons (10, 25, 50 and 645 MeV), ions of boron, carbon and neon, and X-rays (180 keV) within the dose range from 25 to 750 cGy and injected with a radioprotector. Animals were subjected to a single exposure. The protective effect of β-mercaptoethylamine was tested in the experiment. The radioprotector (0.2 ml) was introduced intraperitoneally 30 minutes before exposure in 350 mI/kg dose. Control animals received the same amount of sodium chloride solution. The animals were sacrificed by cervical dislocation in 24 and 72 hrs. after exposure. It was shown that cysteamine effectively protects in vivo corneal epithelium cells of mice exposed to electromagnetic radiation or protons in a broad energy spectrum (10 to 645 MeV), and to a broad range of radiation doses (25 to 750 cGy), as judged from levels of aberrant mitosis and mitotic activity. The radioprotector exhibited the highest effectiveness in animals exposed to the doses of 50 to 300 cGy. These findings prove that cysteamine may potentially be used for pharmacological protection from protons. The radioprotector failed to prevent chromosomal aberrations after exposure to heavy charged particles of boron, carbon and neon, which implies the need to design radioprotectors against this type of corpuscular radiation specifically.

[Cytogenetic damage to the corneal epithelium of mice due to the in vivo exposure to ionizing radiation with different levels of linear energy transfer]

Damages to corneal epithelium cells were studied in mice irradiated by protons with the energies of 10, 25, 50 and 645 MeV, 60Co γ-quanta and accelerated ions of boron, carbon and neon with the energies of 7.5; 2.5 and 6.0 MeV/nucleon, respectively. X-rays (180 keV) were used as a standard radiation. Animals were exposed to a single dose in the range from 25 to 760 cGy. The mitotic index and aberrant mitoses were counted in corneal preparations in 24 hrs after irradiation. No matter the type of radiation, the mitotic index had an inverse dose dependence, i.e. the higher the dose, the lower the mitotic index. Exposure to all types of radiation resulted in a sharp increase in the number of chromosomal aberrations in the corneal epithelium; frequency of aberrations was a function of dose and type of radiation. The number of chromosomal aberrations displayed a peculiar direct dose dependence irrespective of type of radiation; however, heavy ions of carbon and boron are the most damaging to the cytogenetic apparatus of epithelial cells. Protons at the Bragg peak and ensuing fall, and of 50 MeV also contribute to the production of chromosomal aberrations as compared with sparsely ionizing gamma- and X-rays and high-energy protons with low linear energy transfer. Coefficients of relative biological effectiveness were calculated based on the mitotic index and evidence of aberrant mitosis.

[DEMONSTRATION OF LIKELIHOOD OF THE NEGATIVE EFFECT OF PHYSICAL PROTECTION DURING TOTAL PROTON IRRADIATION OF MICE]

The experiments were performed with outbred CD-1 male mice (SPF category). Total irradiation at 1.0; 2.5 and 5.0 Gy by protons with the average energy of 170 MeV was conducted in a level medical beam of the phasotron at the Joint Institute of Nuclear Investigations. Targets were 2 points of in-depth dose distribution, i.e. beam entrance of the object, and modified Bragg peak. As a physical protector, the comb filter increases linear energy transfer (LET) of 170 MeV entrance protons from 0.49 keV/μm to 1.6 keV/μm and, according to the bone marrow test, doubles the biological effectiveness of protons when comparing radiation doses that cause 37% inhibition of blood cell formation in the bone marrow. Physical protection increases dose rate from 0.37 Gy/min for entrance protons to 0.8 Gy/min for moderated protons which more than in thrice reduces time of irradiation needed to reach an equal radiobiological effect.

[IMMEDIATE RADIOBIOLOGICAL EFFECTS IN MICE FOLLOWING γ-IRRADIATION BY LOW DOSES]

Outbred CD-1 mice females aged 4 to 4.5-months were investigated in 21-22 hours following total γ-irradiation at 10, 25, 50, 75, 100 and 200 mGy. Loss in bone marrow karyocytes, as well as spleen and thymus mass reductions were significant in the group of animals irradiated at 50 and 200 mGy and less dramatic in mice irradiated at 75 mGy. The orientative-trying behavior reaction (OTBR) in the open field tested in 19-20 hours after exposure to 10 and 25 mGy was reliably stronger than in the group of biological control; however, emotional status (ES) in the animals that received 10 mGy dropped significantly. Mice irradiated at 50 mGy were found to weaken the grip of their front limbs. Dose levels differing in opposite radiobiological effects on the parameters under study were established. Doses in the range from 10 to 25 mGy maximized OTBR and ES, while doses of 50, 100 and 200 mGy produced high reactions of the immune and hemopoietic organs.

[MODIFICATION OF THE PROTON BEAM PHYSICAL PARAMETERS AND RADIOBIOLOGICAL CHARACTERISTICS BY ELEMENTS OF SPACECRAFT RADIATION PROTECTION]

The experiment was performed with outbred ICR (CD-1). female mice (SPF). The animals were irradiated by 171 MeV protons at a dose of 20 cGy. The spacecraft radiation protection elements used in the experiment were a construction of wet hygiene wipes called a "protective blind", and a glass plate imitating an ISS window. Physical obstacles on the path of 171 MeV protons increase their linear energy transfer leading to the absorbed dose elevation and strengthening of the radiobiological effect. In the experiment, two types of obstacles together raised the absorbed dose from 20 to 23.2 cGy. Chemically different materials (glass and water in the wipes) were found to exert unequal modifying effects on physical and biological parameters of the proton-irradiated mice. There was a distinct dose-dependent reduction of bone marrow cellularity within the dose range from 20 cGy to 23.2 cGy in 24 hours after exposure. No modifying effect of the radiation protection elements on spontaneous motor activity was discovered when compared with entrance protons. The group of animals protected by the glass plate exhibited normal orientative-trying reactions and weakened grip with the forelimbs. Rationalization of physical methods of spacecrew protection should be based as on knowledge in physical dosimetry (ionizing chambers, thermoluminescent, track detectors etc.), so the radiobiological criteria established in experiments with animals.