RESUMEN

Transforming growth factor-ß1 (TGF-ß1), a cytokine with immunosuppressive and pro-fibrogenic activity, is a potential marker of infection, liver transplant rejection, and fibrosis. Its levels in the blood and tissues depend on many factors; however, the role of gene polymorphism is still unclear. In this work, the distribution frequency of three single nucleotide polymorphism (SNP) variants of the Tgfb1 gene, namely rs1800469, rs1800470, and rs1800471, was studied in children with end-stage liver disease (ESLD). The study included 225 pediatric liver recipients aged 1 month to 16 years (median, 8 months), including 100 boys and 125 girls, and 198 healthy individuals aged 32.7 ± 9.6 years, including 78 men and 120 women. The indication for liver transplantation in children was ESLD, which was mostly caused by congenital and inherited liver diseases. SNPs were detected by real-time polymerase chain reaction using TaqMan probes and DNA isolated from peripheral blood. SNP frequency distribution was in Hardy-Weinberg equilibrium and did not differ between children with liver diseases and the healthy ones. Analysis of the SNPs frequency based on allelic interaction models did not reveal any differences between patients and the healthy individuals. Evaluation of linkage disequilibrium for Tgfb1 polymorphic variant pairs revealed a statistically significant linkage between all studied variants. Seven haplotypes, which are variants of SNP combinations, were observed in the studied groups of patients and healthy individuals. A total of 80% of the group had three haplotypes, whose frequencies did not differ between patients and the healthy individuals. Significant differences were found in the frequency of the haplotypes A-A-C, G-G-C, and G-A-G (at rs1800469, rs1800470, and rs1800471, respectively), which were observed up to 11 times more often in recipients compared to the healthy individuals. It is possible that these haplotypes are ESLD-predisposing variants, which may also contribute to the development of complications after liver transplantation in children.

RESUMEN

Developing technologies for efficient targeted drug delivery for oncotherapy requires new methods to analyze the features of micro- and nanoscale distributions of antitumor drugs in cells and tissues. A new approach to three-dimensional analysis of the intracellular distribution of cytostatics was developed using fluorescence scanning optical-probe nanotomography. A correlative analysis of the nanostructure and distribution of injected doxorubicin in MCF-7 human breast adenocarcinoma cells revealed the features of drug penetration and accumulation in the cell. The technology is based on the principles of scanning optical probe nanotomography and is applicable to studying the distribution patterns of various fluorescent or fluorescence-labelled substances in cells and tissues.

Asunto(s)

RESUMEN

Nanoscale morphological features of branched processes of glial cells may be of decisive importance for neuron-astrocyte interactions in health and disease. The paper presents the results of a correlation analysis of images of thin processes of astrocytes in nervous tissue of the mouse brain, which were obtained by scanning probe microscopy (SPM) and transmission electron microscopy (TEM) with high spatial resolution. Samples were prepared and imaged using a unique hardware combination of ultramicrotomy and SPM. Astrocyte details with a thickness of several tens of nanometers were identifiable in the images, making it possible to reconstruct the three-dimensional structure of astrocytic processes by integrating a series of sequential images of ultrathin sections of nervous tissue in the future.

Asunto(s)

RESUMEN

The development of effective biomedical technologies using magnetic nanoparticles (MNPs) for the tasks of oncotherapy and nanodiagnostics requires the development and implementation of new methods for the analysis of micro- and nanoscale distributions of MNPs in the volume of cells and tissues. The paper presents a new approach to three-dimensional analysis of MNP distributions - scanning magnetic force nanotomography as applied to the study of tumor tissues. Correlative reconstruction of MNP distributions and nanostructure features of the studied tissues made it possible to quantitatively estimate the parameters of three-dimensional distributions of composite nanoparticles based on silicon and iron oxide obtained by femtosecond laser ablation and injected intravenously and intratumorally into tumor tissue samples of B16/F1 mouse melanoma. The developed technology based on the principles of scanning probe nanotomography is applicable for studying the features of three-dimensional micro- and nanoscale distributions of magnetic nanoparticles in biomaterials, cells and tissues of various types.

Asunto(s)

RESUMEN

Creation of new effective bio-artificial structures for tissue engineering and regenerative medicine requires development and implementation of new technological approaches for analysis of micro- and nanostructural features of constructs based on biomaterials and their interaction with cells. A new method of three-dimensional multiparametric analysis of nanostructure, scanning optical probe nanotomography, is presented in this paper, applied to the analysis of cells and biomaterials. Correlative reconstruction of fluorescent marker distributions and nanostructure features allows quantitative evaluation of a number of parameters of three-dimensional nanomorphology of fibroblasts and human hepatocarcinoma cells Hep-G2, adhered to biodegradable scaffolds based on silk fibroin. The developed technology with use of scanning optical probe nanotomography is applicable to investigation of three-dimensional micro- and nanostructure features of biomaterials and cells of different types.

Asunto(s)

RESUMEN

The obtaining of microcarriers for the cell culture and delivery is an urgent task of tissue engineering and regenerative medicine. The novel method of surface modification of alginate microcarriers in the form of microspheres with a diameter of 200-300 µm was developed. The described method consists in covalent crosslinking between collagen and surface of alginate microcarriers. It was shown that the method makes it possible to completely modify the surface of the alginate microcarrier, which can be used to improve the biological properties of the microcarrier. Such microcarriers with improved biological properties can be considered as effective systems for cell delivery and culture.

Asunto(s)

Asunto(s)

Asunto(s)

RESUMEN

OBJECTIVE: The aim of the work was to develop a standard protocol of colour velocity and spectral Doppler ultrasound (D.-US) of liver tumour vascularization and to estimate the value of this method in differentiation of liver tumours. METHODS: In 1994 and 1995, 68 patients with 128 primary and secondary liver tumours were observed. The final diagnosis was histologically verified. The diagnostic system Acuson 128 X/P 10M (Mountain View, CA) with 3.5 MHz convex abdominal probe was used. Qualitative features (vessel presence, vessel location and waveform of tumour vessel blood flow) and quantitative features (vessel quantity per cm2, vessel diameter, maximum velocity (Vmax), and resistance index (RI) of tumour artery, and Vmax of tumour portal vein) were included in the D.-US protocol. The differences in these features among various liver tumours were retrospectively analysed. RESULTS: The tumour vascularization was found more frequently in hepatocellular carcinoma (HCC) than in cavernous hemagioma (CavHA) or metastatic liver lesion (MLL) (P<0. 01). Among the tumours with detected vascularization, significant differences (P<0.01) were found (1) in vessel presence: (a) around tumour between MLL and HCC with or without liver cirrhosis (LC) or CavHA; (b) in periphery of tumour between HCC,CavHA, benign tumour (BT; hepatocellular adenoma, focal nodular hyperplasia) and MLL; (2) in detection rate of arterial blood flow between HCC with or without LC and CavHA or MLL. The other differences were not statistically significant. CONCLUSIONS: According to our findings D.-US can be used for the differentiation of some liver tumours when using the criteria: (a) vessel presence around or in periphery of tumour, and (b) arterial flow pattern in tumour vessels.

Asunto(s)