Tritium-Labeled Nanodiamonds as an Instrument to Analyze Bioprosthetic Valve Coatings: A Case of Using a Nanodiamond Containing Coating on a Pork Aorta.

Coatings with xenogenic materials, made of detonation nanodiamonds, provide additional strength and increase elasticity. A functionally developed surface of nanodiamonds makes it possible to apply antibiotics. Previous experiments show the stability of such coatings; however, studies on stability in the bloodstream and calcification of the material in natural conditions have yet to be conducted.

Influence of γ-Radiation on Mechanical Stability to Cyclic Loads Tubular Elastic Matrix of the Aorta.

A significant drawback of the rigid synthetic vascular prostheses used in the clinic is the mechanical mismatch between the implant and the prosthetic vessel. When placing prostheses with radial elasticity, in which this deficiency is compensated, the integration of the graft occurs more favorably, so that signs of cell differentiation appear in the prosthesis capsule, which contributes to the restoration of vascular tone and the possibility of vasomotor reactions. Aortic prostheses fabricated by electrospinning from a blend of copolymers of vinylidene fluoride with hexafluoropropylene (VDF/HFP) had a biomechanical behavior comparable to the native aorta.

[SCREENING ASSESSMENT OF MATERIALS THROMBOGENICITY BY THE NUMBER OF PLATELETS ADHERED FROM THE FLOWING NATIVE BLOOD].

The materials used in the construction of implants contacting with blood should be resistant to thrombus formation. One of the stages of a thrombogenicity assessment of materials is to determine the number of platelets adhered to its surface during the exposure to flowing blood under ex viAvo conditions. The aim of this study was to develop a modified test for screening assessment of materials for their thrombogenicity in contact with native blood.

The Effect of Mechanical Compatibility and of Thrombogenicity on the Ingrowth of a New Synthetic Vascular Prosthesis (Experimental Study).

Common disadvantages of modern synthetic vascular prostheses are thrombogenicity and lack of biomechanical compatibility with the prothesized vessel. To elucidate the role of these factors in the prosthesis integration, prostheses specimens were made by the electrospinning from the known materials: polycaprolactone, polyurethane and a mixture of fluorine-containing synthetic rubber FKM-26 with fluoroplastic F-26. The germination of the prostheses was compared with standard e-PTFE prosthesis in the pigs infrarenal aorta.

Assessment of the Chemosensitivity of Uveal Melanoma Cells Ex Vivo.

The study was designed to create a primary cell culture of uveal melanoma and to evaluate its resistance to chemotherapy. Of the obtained 20 samples of uveal melanoma, the primary cultures with proliferation sufficient for MTT test were derived in only 7 cases. However, even these cultures were unable to survive more than 4 passages; the cells accumulated melanin and underwent apoptosis.

The Effect of Mechanical Properties of Synthetic Prostheses Made by Electrospinning on the Results of Experimental Implantation in the Infrarenal Abdominal Aorta.

Background: The research aims to study the effect of circumferential compliance of synthetic vascular prostheses on their healing during implantation in the infrarenal abdominal aorta of pigs.

Methods: In an experiment, 12 pigs were implanted with blood vessel prostheses in the infrarenal abdominal aorta. The prostheses possessed elastic characteristics obtained by a tensile testing machine, and differed in circumferential compliance: rigid (polycaprolactone [PCL]); less compliant than the native aorta (polyurethane [PU]); comparable in compliance to the native aorta (copolymer of vinylidene fluoride with hexafluoropropylene) before (FKM) and after radiation treatment (FKM-γ).

Retinoblastoma Cell Culturing and Evaluation of Their Drug Resistance.

We obtained primary culture of retinoblastoma cells and evaluated the resistance of cultured ells to chemotherapy. The study included 19 patients aged 6-64 months (mean 27.9±17.

[Malignant medulloepithelioma mimicking retinoblastoma - clinical and morphological case analysis and cell culture experience].

The paper presents clinical and morphological case analysis of primary intraocular malignant medulloepitelioma (medulloblastoma) of rare localization (central part of the retina with optic nerve involvement) that simulated retinoblastoma in a 2-year-old child. Histological features of the tumor are given in details (tubular and mesh structures of the tumor, rosettes, ribbons, cells with hyperchromic nuclei, and cellular polymorphism). An experience of creating a primary intraocular malignant medulloepitelioma cell culture, as yet exclusive in the Russian Federation, is described.

[Pathological and molecular genetic characteristics in patients with extrabulbar growth of uveal melanoma].

Aim: to analyze the association of extrabulbar tumor growth with pathological and molecular genetic changes in patients with uveal melanoma (UM).

Subjects And Methods: A total of 134 UM patients aged 22 to 84 years were examined and treated. The mean height of the tumor was 9.

Analysis of two formaldehyde oxidation pathways in Methylobacillus flagellatus KT, a ribulose monophosphate cycle methylotroph.

The roles of cyclic formaldehyde oxidation via 6-phosphogluconate dehydrogenase and linear oxidation via the tetrahydromethanopterin (H4MPT)-linked pathway were assessed in an obligate methylotroph, Methylobacillus flagellatus KT, by cloning, sequencing and mutating two chromosomal regions containing genes encoding enzymes specifically involved in these pathways: 6-phosphogluconate dehydrogenase, glucose-6-phosphate dehydrogenase and methenyl H4MPT cyclohydrolase (gndA, zwf and mch). No null mutants were obtained in gndA or zwf, implying that the cyclic oxidation of formaldehyde is required for C1 metabolism in this obligate methylotroph, probably as the main energy-generating pathway. In contrast, null mutants were generated in mch, indicating that the H4MPT-linked pathway is dispensable.

Organization of threonine biosynthesis genes from the obligate methylotroph Methylobacillus flagellatus.

The genes encoding aspartate kinase (ask), homoserine dehydrogenase (hom), homoserine kinase (thrB) and threonine synthase (thrC) from the obligate methylotroph Methylobacillus flagellatus were cloned. In maxicells hom and thrC directed synthesis of 51 and 48 kDa polypeptides, respectively. The hom, thrB and thrC genes and adjacent DNA areas were sequenced.

Refined genetic map of the obligate methylotroph Methylobacillus flagellatum.

We present a refined genetic map of the obligate methylotroph Methylobacillus flagellatum. New, Hfr (high-frequency-of-transfer) donors, and pulsed-field gel electrophoresis, were used to determine that M. flagellatum contains one approximately 3.

Organization of methylamine utilization genes (mau) in 'Methylobacillus flagellatum ' KT and analysis of mau mutants.

The organization of genes involved in utilization of methylamine (mau genes) was studied in the obligate methylotroph 'Methylobacillus flagellatum' KT. Nine open reading frames were identified as corresponding to the genes mauFBEDAGLMN. In addition, an open reading frame (orf-1 encoding a polypeptide with unknown function was identified upstream of the mau gene cluster.

Regulation of ammonia assimilation in an obligate methylotroph Methylobacillus flagellatum under steady-state and transient growth conditions.

The obligate methylotroph Methylobacillus flagellatum was grown in the presence of different ammonium concentrations and the regulation of the enzymes associated with ammonium assimilation was investigated in steady-state and transient growth regimes. As the medium changed from C-limitation to dual C/N- and finally to N-limitation, the culture passed through three definite growth phases. The NADP(+)-dependent glutamate dehydrogenase (GDH) was present under ammonium limitation of the culture growth (at 2 mmol 1(-1) of ammonium in the growth medium) and increased in response to an increase in nitrogen availability.

Two new members of the bio B superfamily: cloning, sequencing and expression of bio B genes of Methylobacillus flagellatum and Corynebacterium glutamicum.

Cloning, characterization and expression of the bio B gene of the obligate methylotrophic bacterium, Methylobacillus flagellatum, are reported. A chromosomal fragment containing bio B has been isolated by complementation of a bio B- mutant of M. flagellatum.

Identification and characterization of the pqqDGC gene cluster involved in pyrroloquinoline quinone production in an obligate methylotroph Methylobacillus flagellatum.

Pyrroloquinoline quinone is a prosthetic group of bacterial methanol dehydrogenases as well as some alcohol and glucose dehydrogenases. Genes involved in pyrroloquinoline quinone production have previously been cloned from the representatives of the alpha and gamma subdivisions of the Proteobacteria. We report identification and the sequence of the pqqDGC gene cluster in the obligate methylotroph, Methylobacillus flagellatum, which belongs to the beta subdivision.

(2)H- and(13)C-labeled amino acids generated by obligate methylotrophs Biosynthesis and MS monitoring.

Biosynthetic preparation of(2)H- and(13)C- labeled amino acids was studied using a leucine-producing mutant of the obligate methylotroph,Methylobacillus flagellatum. The strain was cultivated in various media containing(13)C- or(2)H-analogs of methanol. The total protein from each experiment was subjected to acid hydrolysis and converted into a mixture of dansyl amino acid methyl esters.

Formate dehydrogenase from methylotrophic bacterium Pseudomonas sp. 101: gene cloning and expression in Escherichia coli.

Using two degenerate 20- and 23-mer oligonucleotide probes, the gene encoding NAD(+)-dependent formate dehydrogenase (FDH) (EC 1.2.1.

Growth of the obligate methylotroph Methylobacillus flagellatum under stationary and nonstationary conditions during continuous cultivation.

The growth characteristics of a chemostat culture of the obligate methylotrophic bacterium Methylobacillus flagellatum have been determined. Steady-state cultures growing at a rate of 0.73-0.

Growth and enzymological characteristics of a pink-pigmented facultative methylotroph Methylobacterium sp. MB1.

Growth characteristics of batch and continuous cultures of the pink facultative methylotroph Methylobacterium sp. MB1 were determined. The response of a chemostat culture to a pulse increase of methanol concentration was studied.

Genetic organization of methylamine utilization genes from Methylobacterium extorquens AM1.

An isolated 5.2-kb fragment of Methylobacterium extorquens AM1 DNA was found to contain a gene cluster involved in methylamine utilization. Analysis of polypeptides synthesized in an Escherichia coli T7 expression system showed that five genes were present.

Oxidative and assimilative enzyme activities in continuous cultures of the obligate methylotroph Methylobacillus flagellatum.

In methanol-limited continuous cultures of the obligate methylotrophic bacterium Methylobacillus flagellatum grown at rates from 0.05 to 0.63 h-1, and also in an oxyturbidostat culture of M.

Nucleotide sequence of the amicyanin gene from Methylobacterium extorquens AM1.

The gene for amicyanin from the methylotrophic bacterium, Methylobacterium extorquens AM1 was identified. It encodes a protein consisting of 119 amino acids with a molecular weight of 12,609 kDa. The amino acid sequence shows the presence of a typical leader sequence and signal peptidase recognition site.