[Development and preclinical studies of insulating membranes based on poly-3-hydroxybutyrate-co-3-hydroxyvalerate for guided bone regeneration]

Bone tissue damages are one of the dominant causes of temporary disability and developmental disability. Currently, there are some methods of guided bone regeneration employing different osteoplastic materials and insulation membranes used in surgery. In this study, we have developed a method of preparation of porous membranes from the biopolymer poly-3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV), produced by a strain of Azotobacter chroococcum 7B. The biocompatibility of the porous membranes was investigated in vitro using mesenchymal stem cells (MSCs) and in vivo on laboratory animals. The cytotoxicity test showed the possibility of cell attachment on membrane and histological studies confirmed good insulating properties the material. The data obtained demonstrate the high biocompatibility and the potential application of insulating membranes based on PHBV in bone tissue engineering.

[Biocompatibility of electrospun poly(3-hydroxybutyrate) and its composites scaffolds for tissue engineering]

Development of biodegradable polymers-based scaffolds for tissue engineering is a promising trend in bioengineering. The electrospun scaffolds from poly(3-hydroxybutyrate) (PHB) were produced using different additives that changed the physical and chemical characteristics of the products. As a result, the construct consisting of interwoven threads of different diameter (0.8-3.4 mm) were obtained, the smallest diameter was observed in the threads from the PHB using tetrabutilammonium iodide (TBAI) and titanium oxide II (TiO2) as additives. Mesenchymal stem cells (MSC) were cultivated on the scaffolds for the biocompatibility evaluation of obtained materials. Cells viability was determined by the XTT assay test. It was shown that the scaffold from the interwoven threads of lowest diameter is most favorable for MSC growth in comparison with the polymer film and scaffolds from the threads of larger diameter. Thus, it was shown that the biocompatibility of electrospun PHB scaffolds depended on their microstructure. The obtained data can be used for development of scaffolds for tissue engineering.

[Combined use of tumor markers and MRI tomography in differential diagnosis of ovarian neoplasms]

15 women with indeterminate diagnosis of ovarian lesion have undergone a standard examination, NMR tomography and enzyme immunoassay for tumor markers (KA-125, KA-19-9, CEA). NMR-tomography appeared highly informative in differentiating benign and malignant tumors of the ovaries, effective in staging. The oncomarkers are effective in screening for cancer risk groups, control of treatment efficacy and the disease prognosis. Carbohydrate (tumor-associated) antigen KA-125 is most specific for ovarian cancer. Combined use of the tumor markers and NMR-tomography provides a reliable diagnosis.

[The differential diagnosis of a tumor of the large intestine and ovaries]

Symptomatic of the affection of the large intestine are gastrointestinal discomfort presenting with disturbances in the intestinal passage, tendency toward persistent constipation, anemia of obscure genesis of longstanding, local pain, habitual or spasmodic, severe tenderness on the tumour. The main complaints in the affection of the ovaries include abrupt enlargement of abdomen in size, with the pain symptom being mild; in case it occurs, it has no clear-cut position; no complaints of the intestinal discomfort, the tumour is not tender, no anemia.