Variants of a major DNA satellite discriminate parental subgenomes in a hybrid parthenogenetic lizard Darevskia unisexualis (Darevsky, 1966).

Hybrid parthenogenetic animals are an exceptionally interesting model for studying the mechanisms and evolution of sexual and asexual reproduction. A diploid parthenogenetic lizard Darevskia unisexualis is a result of an ancestral cross between a maternal species Darevskia raddei nairensis and a paternal species Darevskia valentini and presents a unique opportunity for a cytogenetic and computational analysis of a hybrid karyotype. Our previous results demonstrated a significant divergence between the pericentromeric DNA sequences of the parental Darevskia species; however, an in-depth comparative study of their pericentromeres is still lacking. Here, using target sequencing of microdissected pericentromeric regions, we reveal and compare the repertoires of the pericentromeric tandem repeats of the parental Darevskia lizards. We found species-specific sequences of the major pericentromeric tandem repeat CLsat, which allowed computational prediction and experimental validation of fluorescent DNA probes discriminating parental chromosomes within the hybrid karyotype of D. unisexualis. Moreover, we have implemented a generalizable computational method, based on the optimization of the Levenshtein distance between tandem repeat monomers, for finding species-specific fluorescent probes for pericentromere staining. In total, we anticipate that our comparative analysis of Darevskia pericentromeric repeats, the species-specific fluorescent probes that we found and the pipeline that we developed will form a basis for the future detailed cytogenomic studies of a wide range of natural and laboratory hybrids.

Proof of concept for the sapphire scalpel combining tissue dissection and optical diagnosis.

OBJECTIVES: The development of compact diagnostic probes and instruments with an ability to direct access to organs and tissues and integration of these instruments into surgical workflows is an important task of modern physics and medicine. The need for such tools is essential for surgical oncology, where intraoperative visualization and demarcation of tumor margins define further prognosis and survival of patients. In this paper, the possible solution for this intraoperative imaging problem is proposed and its feasibility to detect tumorous tissue is studied experimentally. METHODS: For this aim, the sapphire scalpel was developed and fabricated using the edge-defined film-fed growth technique aided by mechanical grinding, polishing, and chemical sharpening of the cutting edge. It possesses optical transparency, mechanical strength, chemical inertness, and thermal resistance alongside the presence of the as-grown hollow capillary channels in its volume for accommodating optical fibers. The rounding of the cutting edge exceeds the same for metal scalpels and can be as small as 110 nm. Thanks to these features, sapphire scalpel combines tissue dissection with light delivering and optical diagnosis. The feasibility for the tumor margin detection was studied, including both gelatin-based tissue phantoms and ex vivo freshly excised specimens of the basal cell carcinoma from humans and the glioma model 101.8 from rats. These tumors are commonly diagnosed either non-invasively or intraoperatively using different modalities of fluorescence spectroscopy and imaging, which makes them ideal candidates for our feasibility test. For this purpose, fiber-based spectroscopic measurements of the backscattered laser radiation and the fluorescence signals were carried out in the visible range. RESULTS: Experimental studies show the feasibility of the proposed sapphire scalpel to provide a 2-mm-resolution of the tumor margins' detection, along with an ability to distinguish the tumor invasion region, which results from analysis of the backscattered optical fields and the endogenous or exogenous fluorescence data. CONCLUSIONS: Our findings justified a strong potential of the sapphire scalpel for surgical oncology. However, further research and engineering efforts are required to optimize the sapphire scalpel geometry and the optical diagnosis protocols to meet the requirements of oncosurgery, including diagnosis and resection of neoplasms with different localizations and nosologies.

C1s Inhibition by BIVV009 (Sutimlimab) Prevents Complement-Enhanced Activation of Autoimmune Human B Cells In Vitro.

The classical pathway of complement (CP) can mediate C3 opsonization of Ags responsible for the costimulation and activation of cognate B lymphocytes. In this manner, the complement system acts as a bridge between the innate and adaptive immune systems critical for establishing a humoral response. However, aberrant complement activation is often observed in autoimmune diseases in which C3 deposition on self-antigens may serve to activate self-reactive B cell clones. In this study, we use BIVV009 (Sutimlimab), a clinical stage, humanized mAb that specifically inhibits the CP-specific serine protease C1s to evaluate the impact of upstream CP antagonism on activation and proliferation of normal and autoimmune human B cells. We report that BIVV009 significantly inhibited complement-mediated activation and proliferation of primary human B cells. Strikingly, CP antagonism suppressed human Ig-induced activation of B cells derived from patients with rheumatoid arthritis. These results suggest that clinical use of CP inhibitors in autoimmune patients may not only block complement-mediated tissue damage, but may also prevent the long-term activation of autoimmune B cells and the production of autoantibodies that contribute to the underlying pathologic condition of these diseases.

Rapid estimation of tumor cell percentage in brain tissue biopsy samples using inline cartridge extraction mass spectrometry.

Tumor cell percentage (TCP) is an essential characteristic of biopsy samples that directly affects the sensitivity of molecular testing in clinical practice. Apart from clarifying diagnoses, rapid evaluation of TCP combined with various neuronavigation systems can be used to support decision making in neurosurgery. It is known that ambient mass spectrometry makes it possible to rapidly distinguish healthy from malignant tissues. In connection with this, here we demonstrate the possibility of using non-imaging ambient mass spectrometry to evaluate TCP in glial tumor tissues with a high degree of confidence. Molecular profiles of histologically annotated human glioblastoma tissue samples were obtained using the inline cartridge extraction ambient mass spectrometry approach. XGBoost regressors were trained to evaluate tumor cell percentage. Using cross-validation, it was estimated that the TCP was determined by the regressors with a precision of approximately 90% using only low-resolution data. This result demonstrates that ambient mass spectrometry provides an accurate method todetermine TCP in dissected tissues even without implementing mass spectrometry imaging. The application of such techniques offers the possibility to automate routine tissue screening and TCP evaluation to boost the throughput of pathology laboratories. Rapid estimation of tumor cell percentage during neurosurgery.

Metabolic stress is a barrier to Epstein-Barr virus-mediated B-cell immortalization.

Epstein-Barr virus (EBV) is an oncogenic herpesvirus that has been causally linked to the development of B-cell and epithelial malignancies. Early after infection, EBV induces a transient period of hyperproliferation that is suppressed by the activation of the DNA damage response and a G1/S-phase growth arrest. This growth arrest prevents long-term outgrowth of the majority of infected cells. We developed a method to isolate and characterize infected cells that arrest after this early burst of proliferation and integrated gene expression and metabolic profiling to gain a better understanding of the pathways that attenuate immortalization. We found that the arrested cells have a reduced level of mitochondrial respiration and a decrease in the expression of genes involved in the TCA cycle and oxidative phosphorylation. Indeed, the growth arrest in early infected cells could be rescued by supplementing the TCA cycle. Arrested cells were characterized by an increase in the expression of p53 pathway gene targets, including sestrins leading to activation of AMPK, a reduction in mTOR signaling, and, consequently, elevated autophagy that was important for cell survival. Autophagy was also critical to maintain early hyperproliferation during metabolic stress. Finally, in assessing the metabolic changes from early infection to long-term outgrowth, we found concomitant increases in glucose import and surface glucose transporter 1 (GLUT1) levels, leading to elevated glycolysis, oxidative phosphorylation, and suppression of basal autophagy. Our study demonstrates that oncogene-induced senescence triggered by a combination of metabolic and genotoxic stress acts as an intrinsic barrier to EBV-mediated transformation.

Structural and biochemical studies of HCMV gH/gL/gO and Pentamer reveal mutually exclusive cell entry complexes.

Human cytomegalovirus (HCMV) is a major cause of morbidity and mortality in transplant patients and the leading viral cause of birth defects after congenital infection. The glycoprotein complexes gH/gL/gO and gH/gL/UL128/UL130/UL131A (Pentamer) are key targets of the human humoral response against HCMV and are required for HCMV entry into fibroblasts and endothelial/epithelial cells, respectively. We expressed and characterized soluble forms of gH/gL, gH/gL/gO, and Pentamer. Mass spectrometry and mutagenesis analysis revealed that gL-Cys144 forms disulfide bonds with gO-Cys351 in gH/gL/gO and with UL128-Cys162 in the Pentamer. Notably, Pentamer harboring the UL128-Cys162Ser/gL-Cys144Ser mutations had impaired syncytia formation and reduced interference of HCMV entry into epithelial cells. Electron microscopy analysis showed that HCMV gH/gL resembles HSV gH/gL and that gO and UL128/UL130/UL131A bind to the same site at the gH/gL N terminus. These data are consistent with gH/gL/gO and Pentamer forming mutually exclusive cell entry complexes and reveal the overall location of gH/gL-, gH/gL/gO-, and Pentamer-specific neutralizing antibody binding sites. Our results provide, to our knowledge, the first structural view of gH/gL/gO and Pentamer supporting the development of vaccines and antibody therapeutics against HCMV.

In Vitro Characterization of Human Cytomegalovirus-Targeting Therapeutic Monoclonal Antibodies LJP538 and LJP539.

Human cytomegalovirus (HCMV) infection is usually benign in healthy individuals but can cause life-threatening disease in those with compromised immune systems. Approved drugs available to treat HCMV disease, including ganciclovir, cidofovir, and foscarnet, have significant toxicities that limit their use in certain patient populations. LJP538 and LJP539 are human monoclonal antibodies that are being evaluated as immunoglobulin therapeutics. The antibodies target glycoproteins gB and the gH/gL/UL128/UL130/UL131a pentameric complex, respectively. Here we present an in vitro characterization of these antibodies. We show that LJP538 and LJP539 are more potent than a marketed immunoglobulin at inhibiting HCMV infection of various cell lines relevant to pathogenesis. We find that LJP538 and LJP539 are active against a panel of clinical isolates in vitro and demonstrate minor-to-moderate synergy in combination. Passage of HCMV in the presence of LJP538 or LJP539 alone resulted in resistance-associated mutations that mapped to the target genes. However, no loss of susceptibility to the combination of antibodies was observed for >400 days in culture. Finally, the binding regions of LJP538 and LJP539 are conserved among clinical isolates. Taken together, these data support the use of LJP538 and LJP539 in combination for clinical trials in HCMV patients.

Evaluation of the Acousto-Optic Figure of Merit and the Maximum Value of the Elasto-Optic Constant of Liquids.

The elasto-optic properties of liquids on the basis of the first principles of acousto-optics were theoretically investigated. A relationship for calculating the elasto-optic constant of liquids using only the refractive index was obtained. The refractive index values corresponding to the maximum elasto-optic constant for polar and nonpolar liquids were determined. Calculations for about 100 liquids were performed and compared with known experimental data. This study significantly extends our understanding of the acousto-optic effect and has practical applications for predicting the elasto-optic constant of a liquid and estimating its wavelength dispersion.

Structure and Frictional Properties of Ultrahard AlMgB14 Thin Coatings.

This paper presents the results of studies on AlMgB14-based ceramic coatings deposited on WC-Co hard alloy substrates using RF plasma sputtering. The aim of this work is to study the structure, phase composition, and mechanical properties of AlMgB14-based coatings depending on the sputtering mode. According to the results of the microstructural study, the bias voltage applied to the substrate during the sputtering process significantly contributed to the formation of the coating morphology. Based on the results of compositional and structural studies by energy dispersive X-ray spectroscopy, X-ray diffraction, and Raman spectroscopy, it was found that the coatings are composed of nanocrystalline B12 icosahedrons distributed in an amorphous matrix consisting of Al, Mg, B, and O elements. The nanohardness of the coatings varied from 24 GPa to 37 GPa. The maximum value of the hardness together with the lowest coefficient of friction (COF) equal to 0.12 and wear resistance of 7.5 × 10-5 mm3/N·m were obtained for the coating sputtered at a bias voltage of 100 V. Compared with the COF of the original hard alloy substrate, which is equal to 0.31, it can be concluded that the AlMgB14-based coatings could reduce the COF of WC-based hard alloys by more than two times. The hardness and tribological properties of the coatings obtained in this study are in good agreement with the properties of AlMgB14-based materials obtained by other methods reported in the literature.

Development of Glioblastoma from Stem Cells to a Full-Fledged Tumor.

OBJECTIVE: IDH wild-type glioblastomas (GBM) are one of the most malignant and complex tumors for treatment. The urgent question of new therapeutic and diagnostic tools searching should be resolved based on cellular and molecular pathogenesis mechanisms, which remain insufficiently studied. In this study, we aimed to investigate GBM pathogenesis. MATERIAL AND METHOD: /b > Using the isolation of different GBM cell populations and the cell cultures, animal models, and molecular genetic methods, we tried to clarify the picture of GBM pathogenesis by constructing a projection from different glioma stem cells types to an integral neoplasm. RESULTS: We have shown a potential transformation pathway for both glioma stem cells and four definitive cell populations during gliomagenesis. Moreover, we have characterized each population, taking into account its place in the pathogenetic continuum, with a description of the most fundamental molecular and functional properties. CONCLUSION: Finally, we have formed a complex holistic concept of the pathogenetic evolution of GBM at the cell-population level by integrating our results with the data of the world literature.

Optical Characterization of Thin Films by Surface Plasmon Resonance Spectroscopy Using an Acousto-Optic Tunable Filter.

The paper presents the application of the acousto-optic tunable filter (AOTF) in surface plasmon resonance (SPR) spectroscopy to measure the optical thickness of thin dielectric coatings. The technique presented uses combined angular and spectral interrogation modes to obtain the reflection coefficient under the condition of SPR. Surface electromagnetic waves were excited in the Kretschmann geometry, with the AOTF serving as a monochromator and polarizer of light from a white broadband radiation source. The experiments highlighted the high sensitivity of the method and the lower amount of noise in the resonance curves compared with the laser light source. This optical technique can be implemented for nondestructive testing in the production of thin films in not only the visible, but also the infrared and terahertz ranges.

Perifocal Zone of Brain Gliomas: Application of Diffusion Kurtosis and Perfusion MRI Values for Tumor Invasion Border Determination.

(1) Purpose: To determine the borders of malignant gliomas with diffusion kurtosis and perfusion MRI biomarkers. (2) Methods: In 50 high-grade glioma patients, diffusion kurtosis and pseudo-continuous arterial spin labeling (pCASL) cerebral blood flow (CBF) values were determined in contrast-enhancing area, in perifocal infiltrative edema zone, in the normal-appearing peritumoral white matter of the affected cerebral hemisphere, and in the unaffected contralateral hemisphere. Neuronavigation-guided biopsy was performed from all affected hemisphere regions. (3) Results: We showed significant differences between the DKI values in normal-appearing peritumoral white matter and unaffected contralateral hemisphere white matter. We also established significant (p < 0.05) correlations of DKI with Ki-67 labeling index and Bcl-2 expression activity in highly perfused enhancing tumor core and in perifocal infiltrative edema zone. CBF correlated with Ki-67 LI in highly perfused enhancing tumor core. One hundred percent of perifocal infiltrative edema tissue samples contained tumor cells. All glioblastoma samples expressed CD133. In the glioblastoma group, several normal-appearing white matter specimens were infiltrated by tumor cells and expressed CD133. (4) Conclusions: DKI parameters reveal changes in brain microstructure invisible on conventional MRI, e.g., possible infiltration of normal-appearing peritumoral white matter by glioma cells. Our results may be useful for plotting individual tumor invasion maps for brain glioma surgery or radiotherapy planning.

IL-38 blockade induces anti-tumor immunity by abrogating tumor-mediated suppression of early immune activation.

Immune checkpoint inhibitors that overcome T cell suppressive mechanisms in tumors have revolutionized the treatment of cancer but are only efficacious in a small subset of patients. Targeting suppressive mechanisms acting on innate immune cells could significantly improve the incidence of clinical response by facilitating a multi-lineage response against the tumor involving both adaptive and innate immune systems. Here, we show that intra-tumoral interleukin (IL)-38 expression is a feature of a large frequency of head and neck, lung and cervical squamous cancers and correlates with reduced immune cell numbers. We generated IMM20324, an antibody that binds human and mouse IL-38 proteins and inhibits the binding of IL-38 to its putative receptors, interleukin 1 receptor accessory protein-like 1 (IL1RAPL) and IL-36R. In vivo, IMM20324 demonstrated a good safety profile, delayed tumor growth in a subset of mice in an EMT6 syngeneic model of breast cancer, and significantly inhibited tumor expansion in a B16.F10 melanoma model. Notably, IMM20324 treatment resulted in the prevention of tumor growth following re-implantation of tumor cells, indicating the induction of immunological memory. Furthermore, exposure of IMM20324 correlated with decreased tumor volume and increased levels of intra-tumoral chemokines. Together, our data suggest that IL-38 is expressed in a high frequency of cancer patients and allows tumor cells to suppress anti-tumor immunity. Blockade of IL-38 activity using IMM20324 can re-activate immunostimulatory mechanisms in the tumor microenvironment leading to immune infiltration, the generation of tumor-specific memory and abrogation of tumor growth.

Optimal Design of an Ultrasound Transducer for Efficient Acousto-Optic Modulation of Terahertz Radiation.

Acousto-optic (AO) interaction in the terahertz range was investigated with the use of monolithic ultrasound transducers of various widths. Sulfur hexafluoride (SF6) liquefied at a temperature of about 23 °C and a pressure of 25 bar was used as a medium for AO interaction. The angular and frequency bandwidths of effective AO interaction, as well as the diffraction efficiency per 1 W of the driving electric power, were determined. For the first time, a correct comparison of the AO diffraction efficiency in SF6 with the use of ultrasound transducers with different widths was carried out. In the experiments performed, the highest energy efficiency of the AO modulator was achieved with a transducer with a width of 12 mm.

Acousto-Optic Modulation and Deflection of Terahertz Radiation.

It is known that one of the ways to increase the energy efficiency of acousto-optic devices is to use ultrasound beams with a higher power density. It has been established experimentally that the use of a partially electroded ultrasonic transducer significantlyincreases the energy efficiency of the acousto-optic modulator of terahertz radiation. In addition, the operation of an acousto-optic deflector of terahertz radiation with the use of a sectioned ultrasound transducer was theoretically investigated. It showed that a deflector of this kind enables one to achieve higher angular resolution.

Effect of Mechanical Activation of Al-Ti-B Powder Mixture on Phase Composition and Structure of Al-TiB2 Composite Materials Obtained by Self-Propagating High-Temperature Synthesis (SHS).

In this study, we successfully obtained Al-TiB2 composite materials using self-propagating high-temperature synthesis and preliminary mechanical activation of the initial Al-(Ti + 2B) powder mixture with a high aluminum content (70 wt.%). We investigated the possibility of controlling the structure of synthesis products, in particular, the size and shape of ceramic particles. We examined the effects of the mechanical activation of the initial powder mixture on the structure and particle size of titanium diboride in the synthesis products. We proposed a mechanism of structure formation in the synthesis products obtained by SHS using the method of preliminary mechanical activation of the initial mixture. We found that mechanical activation for 60-180 s led to the formation of isolated TiB2 particles of prolate and irregular shape. The average particle size of TiB2 in the synthesis products was 0.77 (after 60 s of mechanical activation) and 1.5 µm (after 180 s of mechanical activation), respectively. An increase in the duration of mechanical activation to 900 s led to the formation of an island (skeletal) structure, in which there were interconnected aggregates and isolated particles of titanium diboride. The average size of these particles was 4.3 µm.

On the Tensile Strength of Spark Plasma Sintered AlMgB14 Ceramics.

In this work, the structure, phase composition, hardness and tensile strength of the AlMgB14-based material obtained by spark plasma sintering (SPS) were investigated. According to the XRD results, the spark plasma sintered material contains 94 wt% AlMgB14 phase and 6 wt% spinel MgAl2O4. Analysis of the SEM images showed that the obtained AlMgB14 sample has a dense structure; the relative density of the sample is 98.6%. The average microhardness of the spark plasma sintered (SPSed) sample is 29 ± 0.88 GPa. According to the results of the Brazilian test, the tensile strength of AlMgB14 is 56 MPa. The fracture is characterized by a single straight tensile crack that divides the sample along the compression line into two halves. The type of fracture in the AlMgB14 sample can be characterized as a cleavage fracture due to crack growth occurring in accordance with the transcrystalline fracture. The tensile strength of the obtained material is in good agreement with the tensile strength of boride and oxide ceramics studied in other works.

Phase Composition, Structure and Properties of the Spark Plasma Sintered Ceramics Obtained from the Al12Mg17-B-Si Powder Mixtures.

In this work, composite materials were obtained by spark plasma sintering of an Al12Mg17-B-Si powder mixture. The structure, phase composition, and mechanical properties of the obtained composites were studied. It was found that various compounds based on B12 icosahedrons, such as AlB12, B4Si, and B6Si, are formed during spark plasma sintering. Based on the SEM images and results of XRD analysis of the obtained specimens, a probable scheme for the formation of the phase composition of composite materials during spark plasma sintering was proposed. An increase in the Al12Mg17-B powder content in the initial mixture from 30 to 70 wt% leads to an increase in hardness from 16.55 to 21.24 GPa and a decrease in the friction coefficient and wear rate from 0.56 to 0.32 and 13.60 to 5.60 10-5 mm-3/(N/m), respectively.

Experimental and Theoretical Study of Ultra-Hard AlMgB14-TiB2 Composites: Structure, Hardness and Self-Lubricity.

It is known that the presence of oxygen phases in hard materials leads to an undesirable decrease in the mechanical properties. In materials based on AlMgB14, the main oxygen impurity is spinel MgAl2O4; it significantly reduces the hardness of AlMgB14 and its formation during sintering is inevitable. In this work, the ultra-hard spark plasma sintered (SPSed) AlMgB14-TiB2 composite material was fabricated from the AlMgB14-TiB2 precursor obtained by self-propagating high-temperature synthesis (SHS). Due to the high synthesis temperatures, the main oxygen phase in the obtained composite was Al4B2O9 instead of spinel MgAl2O4. It was found that the obtained composite has excellent mechanical properties. The maximum hardness of the sample is 44.1 GPa. The presence of oxygen in the form of the Al4B2O9 phase led to unexpected results: the friction coefficient of the obtained AlMgB14-TiB2 composite under dry conditions against the Al2O3 counter-specimen is approximately four times lower than the friction coefficient of pure ceramic AlMgB14 (0.18 against 0.7, respectively). Based on the observed results, it was found that the Al4B2O9 particles formed during the SHS are responsible for the low friction coefficient. The quantum chemical calculations showed that the elastic moduli of Al4B2O9 are significantly smaller than the elastic moduli of AlMgB14 and TiB2. Thus, during sliding, Al4B2O9 particles are squeezed out onto the composite surface, form the lubricating layer and reduce the friction coefficient.

Cell-Population Dynamics in Diffuse Gliomas during Gliomagenesis and Its Impact on Patient Survival.

Diffuse gliomas continue to be an important problem in neuro-oncology. To solve it, studies have considered the issues of molecular pathogenesis from the intratumoral heterogeneity point. Here, we carried out a comparative dynamic analysis of the different cell populations' content in diffuse gliomas of different molecular profiles and grades, considering the cell populations' functional properties and the relationship with patient survival, using flow cytometry, immunofluorescence, multiparametric fluorescent in situ hybridization, polymerase chain reaction, and cultural methods. It was shown that an increase in the IDH-mutant astrocytomas and oligodendrogliomas malignancy is accompanied by an increase in stem cells' proportion and mesenchymal cell populations' appearance arising from oligodendrocyte-progenitor-like cells with cell plasticity and cells' hypoxia response programs' activation. In glioblastomas, malignancy increase is accompanied by an increase in both stem and definitive cells with mesenchymal differentiation, while proneuronal glioma stem cells are the most likely the source of mesenchymal glioma stem cells, which, in hypoxic conditions, further give rise to mesenchymal-like cells. Clinical confirmation was a mesenchymal-like cell and mesenchymal glioma stem cell number, and the hypoxic and plastic molecular programs' activation degree had a significant effect on relapse-free and overall survival. In general, we built a multi-vector model of diffuse gliomas' pathogenetic tracing up to the practical plane.