Quantification of attenuation and speckle features from endoscopic OCT images for the diagnosis of human brain glioma.

Application of optical coherence tomography (OCT) in neurosurgery mostly includes the discrimination between intact and malignant tissues aimed at the detection of brain tumor margins. For particular tissue types, the existing approaches demonstrate low performance, which stimulates the further research for their improvement. The analysis of speckle patterns of brain OCT images is proposed to be taken into account for the discrimination between human brain glioma tissue and intact cortex and white matter. The speckle properties provide additional information of tissue structure, which could help to increase the efficiency of tissue differentiation. The wavelet analysis of OCT speckle patterns was applied to extract the power of local brightness fluctuations in speckle and its standard deviation. The speckle properties are analysed together with attenuation ones using a set of ex vivo brain tissue samples, including glioma of different grades. Various combinations of these features are considered to perform linear discriminant analysis for tissue differentiation. The results reveal that it is reasonable to include the local brightness fluctuations at first two wavelet decomposition levels in the analysis of OCT brain images aimed at neurosurgical diagnosis.

Terahertz dielectric spectroscopy and solid immersion microscopy of ex vivo glioma model 101.8: brain tissue heterogeneity.

Terahertz (THz) technology holds strong potential for the intraoperative label-free diagnosis of brain gliomas, aimed at ensuring their gross-total resection. Nevertheless, it is still far from clinical applications due to the limited knowledge about the THz-wave-brain tissue interactions. In this work, rat glioma model 101.8 was studied ex vivo using both the THz pulsed spectroscopy and the 0.15λ-resolution THz solid immersion microscopy (λ is a free-space wavelength). The considered homograft model mimics glioblastoma, possesses heterogeneous character, unclear margins, and microvascularity. Using the THz spectroscopy, effective THz optical properties of brain tissues were studied, as averaged within the diffraction-limited beam spot. Thus measured THz optical properties revealed a persistent difference between intact tissues and a tumor, along with fluctuations of the tissue response over the rat brain. The observed THz microscopic images showed heterogeneous character of brain tissues at the scale posed by the THz wavelengths, which is due to the distinct response of white and gray matters, the presence of different neurovascular structures, as well as due to the necrotic debris and hemorrhage in a tumor. Such heterogeneities might significantly complicate delineation of tumor margins during the intraoperative THz neurodiagnosis. The presented results for the first time pose the problem of studying the inhomogeneity of brain tissues that causes scattering of THz waves, as well as the urgent need to use the radiation transfer theory for describing the THz-wave - tissue interactions.

[Methods of decreasing the risk of repeat interventions in patients after arterial revascularization]. / Sposoby snizheniia riska povtornogo vmeshatel'stva u patsientov posle arterial'noi revaskuliarizatsii.

Discussed in the article are the main problems related to surgical treatment of patients with peripheral artery disease, particularly taking into consideration that in the world there are from 160 to 202 million people suffering from this disease, with two thirds of such patients having signs of lesions of coronary or cerebral arteries. Vascular reconstructive interventions cannot completely eliminate the problem, since in the postoperative period there may develop cardiovascular complications related to both the limb involved as either acute or progressing chronic ischaemia and arteries of other localization (coronary, cerebral). The risk of serious cardiovascular complications in patients with a history of endured adverse ischaemic events on the part of limbs is severalfold higher. To solve these problems and decrease complications, salicylic acid is used as basic therapy. Attempts at replacing it by another drug or combined therapy with an alternative antiaggregant showed no advantages in increased risk of massive haemorrhage. On the other hand, a combination of salicylic acid with an anticoagulant at a low dose, i. e., rivaroxaban 2.5 mg twice daily as compared with acetylsalicylic acid monotherapy made it possible to significantly decrease the incidence of various cardiovascular complications in the form of myocardial infarction, stroke, adverse ischaemic events on the part of the extremity, limb amputation.

Proteomic Profiling of HL-60 Cells during ATRA-Induced Differentiation.

Acute promyelocytic leukemia, a form of acute myeloid leukemia, is characterized by cell differentiation arrest at the promyelocyte stage. Current therapeutic options include administration of all trans-retinoic acid (ATRA), but this treatment produces many side effects. ATRA is known to induce differentiation of leukemic cells into granulocytes, but the mechanism of this process is poorly studied. We performed comparative proteomic profiling of HL-60 promyelocytic cells at different stages of ATRA-induced differentiation to identify differentially expressed proteins by high-resolution mass spectrometry and relative quantitative analysis without isotope labels. A total of 1162 proteins identified by at least two unique peptides were analyzed, among them 46 and 172 differentially expressed proteins were identified in the nuclear and cytosol fractions, respectively. These differentially expressed proteins can represent candidate targets for combination therapy of acute promyelocytic leukemia.

Analysis of Reparative Activity of Platelet Lysate: Effect on Cell Monolayer Recovery In Vitro and Skin Wound Healing In Vivo.

Platelet lysate prepared from donor platelet concentrate and pooled according to a developed technique stimulates migration of multipotent mesenchymal stromal cells of the human adipose tissue and promotes healing of the monolayer defect in cultures of human fibroblasts and multipotent mesenchymal stromal cells in vitro in concentrations close those of fetal calf serum (5-10%). Lysate of platelets from platelet-rich rat blood plasma stimulated healing of the skin defect by promoting epithelialization and granulation tissue formation. The regenerative properties of platelet lysate in vivo increased with increasing its concentration.

[The influence of doxorubicin incorporated in phospholipid drug delivery nanosystem on HEPG2 cells proteome].

A phospholipid drug delivery nanosystem with particle size up to 30 nm elaborated at the Institute of Biomedical Chemistry has been used earlier for incorporation of doxorubicin (Doxolip). This system demonstrated higher antitumor effect in vivo as compared with free doxorubicin. In this study the effect of this nanosystem containing doxorubicin on HepG2 cell proteome has been investigated. Cells were incubated in a medium containing phospholipid nanoparticles (0.5 mg/ml doxorubicin, 10 mg/mL phosphatidylcholine). After incubation for 48 h their survival represented 10% as compared with untreated cells. Cell proteins were analyzed by quantitative two-dimensional gel electrophoresis followed by identification of differentially expressed proteins with MALDI-TOF mass spectrometry. The phospholipid transport nanosystem itself insignificantly influenced the cell proteome thus confirming previous data on its safety. Doxorubicin, as both free substance and Doxolip (i.e. included into phospholipid nanoparticles) induced changes in expression of 28 proteins. Among these proteins only four of them demonstrated different in response to the effect of the free drug substance and Doxolip. Doxolip exhibited a more pronounced effect on expression of certain proteins; the latter indirectly implies increased penetration of the drug substance (included into nanoparticles) into the tumor cells. Increased antitumor activity of doxorubicin included into phospholipid nanoparticles may be associated with more active increase of specific protein expression.

Implication of α2ß1 integrin in anoikis of MCF-7 human breast carcinoma cells.

Silencing of α2ß1 integrin expression significantly promoted anchorage-dependent apoptosis (anoikis) and drastically reduced clonal activity of MCF-7 human breast carcinoma cells. Depletion of α2ß1 enhanced the production of apoptotic protein p53 and of inhibitor of cyclin-dependent protein kinases, p27, while downregulating antiapoptotic protein Bcl-2 and multifunctional protein cMyc. Blocking the expression of α2ß1 had no effect on activity of protein kinase Akt, but it sharply increased the kinase activity of Erk1/2. Pharmacological inhibition of Erk1/2 had a minor effect on anoikis of control cells, while it reduced anoikis of cells with downregulated α2ß1 to the level of control cells. The data show for the first time that integrin α2ß1 is implicated in the protection of tumor cells from anoikis through a mechanism based on the inhibition of protein kinase Erk.

CD133+ human colorectal adenocarcinoma cells are resistant to staining with fluorescent dyes used for analysis of ABC transporter activities.

Flow cytometry measurement of the expression of surface marker CD133 simultaneously with the analysis of fluorescent dye exclusion was performed in order to develop new methods for detection of cancer stem cell populations in tumor tissue samples from patients with colorectal adenocarcinoma. No correlation was found between the count of CD133(+) cancer cells and the volume of the "population" formed from cells actively pumping off the fluorescent dye. On the other hand, the fluorescence distribution plot showed predominant location of CD133(+) cancer cells among cells stained with neither DyeCycle Violet DNA-binding dye, nor rhodamine 123 mitochondrial dye. These cells did not show the properties of the classical "side population", because they did not shift to the area of stained cell after treatment with ionic channel blocker verapamil.

[Identification of "side population" associated with cancer stem cells by flow cytometry with violet laser].

The possibility of identification of cancer stem cells "side population" in solid tumors by using the flow cytometer equipped with 405 nm violet laser was investigated. Ovarian cancer (Skov-3) and colon cancer (Colo 320) cell lines formed the "side population" after vital staining with Hoechst 33342. Analysis of cells isolated from tumor tissue of malignant melanoma and colorectal cancer, also revealed "side population" that was a result of the fluorescent dye exclusion. The percentage of melanoma cells included in the "side population" was the same as that of cells co-expressing cancer stem cells markers--CD34 and CD44. In contrast, the colon cancer "side population" was significantly smaller than the minor populations of colon cancer cells identified by either CD133 expression or exclusion of Rhodamine 123.

Effect of calcium phosphate materials on multipotent mesenchymal cells from exfoliated deciduous teeth (SHED cells) in vitro.

Various calcium phosphate ceramic materials were created and their effect on cultured mesenchymal cells from exfoliated deciduous tooth pulp was evaluated. Tricalcium phosphate ceramics provides best cell survival and is an optimal material for bone tissue engineering. Analysis of the effects of tricalcium phosphate ceramics on osteogenic differentiation of SHED cells suggests that this material potentiated dexamethasone-induced osteogenic differentiation, which manifested in the increased number of ossification foci and enhanced extracellular matrix production by cells. Thus, the tricalcium phosphate ceramics created by us is a promising biomedical material that can be used for tissue-engineered bone analogs.

[Antitumor activity of L-asparaginase from Erwinia carotovora from against different leukemic and solid tumours cell lines].

We have studied dose- and time-dependent antitumor and cytotoxic effects of Erwinia carotovora L-asparaginase (ECAR LANS) and Escherichia coli L-asparaginase (MEDAC) on human leukemic cells and human and animal solid tumor cells. We determined the sensitivity of tumor cells to L-asparaginases, as well the effect L-asparaginases on cell growth rate, protein and DNA synthesis per se and with addition of different cytostatics. The data obtained demonstrated that ECAR LANS L-asparaginase suppressed growth of all tested solid tumor cells. Evaluation of leukemic cell number after treatment with L-asparaginases for 24, 48 and 72 h demonstrated that asparagine deficiency did not kill cells but stopped normal cell division and had no effect on protein and DNA synthesis. Cytofluorometric study of solid and leukemic cells demonstrated that the treatment with L-asparaginase for 72 h did not change cell cycle phase distribution and did not increase the number of apoptotic cells. The HL-60 cell line was only exemption. At the same time, cells treatment with L-asparaginase and doxorubicin combination leaded to increase of apoptotypical cell number to 60% for MCF7 cells, to 40% for Jurkat cells and to 99% for HL-60 cells. We have excluded apoptosis as main reason for tumor cell death after asparaginase treatment because multi resistant Jurkat/A4 cells have been asparaginase sensitive. We have not found ECAR LANS L-asparaginase effect on normal human fibroblasts growth ability and we had come to conclusion that enzyme cytotoxcisity related only with asparagine deficiency.

[Synthesis and biological activity of probable 24-norbrassinolide biosynthetic precursors].

A number of 24-norbrassinolide biosynthetic precursors containing low polar functional groups (3beta3-OH, 3-keto-, delta2- or 2alpha,3alpha-epoxy-) in A-cycle and (22R,23R)-diol in the side chain has been prepared. Studies of these compounds as proliferation regulators in MCF-7 human breast cancer and LnCaP human prostate adenocarcinoma cells showed that most nonpolar (22R,23R)-derivatives effectively suppressed proliferation. Dependence of proliferation on concentration of studied compounds was found in human prostate carcinoma LnCaP cells (IC50 = 13-28 microM at 72 h of incubation in a medium containing 10% FBS; suppression of DNA biosynthesis). A number of compounds induced apoptosis (23-33%); arrested cell cycle in S- and G2/M-phases; and caused partial cells detachment during prolonged incubations.

Subpopulation of colorectal adenocarcinoma cells co-expressing CD133 and cancer stem cells markers of other tumors.

Co-expression of colorectal adenocarcinoma cancer stem cells marker CD133 and a set of surface molecules described in published reports as possible cancer stem cell markers of other solid tumors was analyzed by flow cytometry. Minor cell populations expressing CD29, CD34, CD90, and CD117 against the background of CD133 expression were detected in cancer cells suspensions from the patients with colorectal adenocarcinoma. Our findings suggest that these markers can be used as additional markers of cancer stem cells of human colorectal adenocarcinoma.

Immunoregulatory properties of human stem cells of mesenchymal and ectodermal origin after their transplantation to BALB/c mice.

We studied immunoregulatory properties of cultured human stem cells of mesenchymal and ectodermal origins after their administration to mice. Xenotransplantation of mesenchymal stem cells from human placenta reduced the number of CD11c(+)dendritic cells in mouse spleens, but did not affect activation of dendritic cells from mouse spleen in culture. It was also shown that splenocytes isolated from animals 10 days after transplantation of mesenchymal stem cells more actively proliferated in response to the polyclonal stimulation. At the same time, transplantation of neither mesenchymal nor neural stem cells affected the ratio of CD4(+)/CD8(+)T cells and their total content in the peripheral blood in comparison with the corresponding parameters in the control groups.

Design of tissue engineering implants for bone tissue regeneration of the basis of new generation polylactoglycolide scaffolds and multipotent mesenchymal stem cells from human exfoliated deciduous teeth (SHED cells).

Cultures of multipotent mesenchymal stromal cells from the pulp of human deciduous teeth (SHED cells) were characterized. The cells were used for population of 3D biodegradable polylactoglycolide scaffolds; their osteogenic potential was preserved under these conditions. Implantation of the scaffolds to mice induced no negative reactions in the recipients. These results suggest that the use of polylactoglycolide scaffolds populated with SHED cells is a promising approach for creation of implants for bone defect replacement.

Detection of minor subpopulations of colorectal adenocarcinoma cells expressing cancer stem cell markers.

The expression of puitative surface molecular markers of cancer stem cells on human colorectal adenocarcinoma cells was analyzed by flow cytofluorometry. Cell subpopulations expressing markers of epithelial and malignant cells and stem cell markers were identified. Four minor subpopulations with CD24(+)/CD133(+), CD44(+)/CD133(+), CD90(+)/CD71(+), or CD90(+)/CD24(+) phenotypes meeting this requirement were detected; presumably, those were cancer stem cell subpopulations. These results extend our knowledge on heterogeneity of human colorectal adenocarcinoma cell population and outline new trends of research of cancer stem cell phenotype in these tumors.

Mesenchymal cells of the decidual tooth pulp: cytophenotype and initial evaluation of possibility of their use in bone tissue engineering.

Cultures of mesenchymal cells from human decidual tooth pulp were derived. The phenotype and capacity to osteogenic and adipogenic differentiation of these cells are close to those of bone marrow mesenchymal stem cells. Decidual tooth pulp mesenchymal cells populate biodegraded polylactide scaffolds and hence, can be used for the creation of tissue engineering transplants for bone defect repair. Storage of decidual tooth pulp mesenchymal cells in the stem cell cryobanks together with umbilical blood will appreciably extent the periods of age for collection of juvenile autologous stem cells for use throughout the life span.

CD24 and CD70 as differential markers of human hepatocellular carcinoma cells in culture.

We developed a new method for evaluation of the purity of cell population in primary cultures of hepatocellular carcinoma. Expression of potential surface molecular markers on primary cultures of renal tumors was assayed by the method of flow cytofluorometry. CD24 and CD70 were identified as differential markers, which allowed us to distinguish cancer cells from tumor stromal cells in vitro. A negative marker CD90 was expressed on fibroblasts of the tumor stroma, but not on cancer cells. Combined use of these three markers allows evaluation of the severity of tumor culture contamination with stromal cells.

Cytofluorometric analysis of phenotypes of human bone marrow and umbilical fibroblast-like cells.

Comparative analysis of the expression of some surface markers of human bone marrow mesenchymal stem cells, umbilical fibroblast-like cells, and skin fibroblasts was carried out by the flow cytofluorometry method. Mesenchymal stem cells and umbilical fibroblast-like cells were similar by the levels of expression of the main histocompatibility complex antigens, adhesion molecules, and some growth factor receptors. The profile of skin fibroblast surface antigens was characterized by higher expression of the markers typical of differentiated cells. The results prove the possibility of using umbilical fibroblast-like cells as an alternative source of mesenchymal stem cells for cell replacement therapy.