Comparative Analysis of Two Enoxaparin Sodium Drugs by Heptest.

The optimal conditions for analysis of low-molecular-weight heparin (LMWH) drugs by the Heptest and the metrological characteristics of the Heptest method were determined. The effects of two LMWH preparations of enoxaparin sodium, the domestic drug Enoxaparin sodium (Technologiya Lekarstv, Russia) and the original drug Clexane (Sanofi, France), on the clotting time of human plasma in the Heptest were comparatively analyzed. The mean blood clotting times were calculated for each dilution of each series of Enoxaparin sodium and Clexane based on the results of the Heptest. Graphs of the dependence of the plasma clotting time on the degree of dilution of these drugs were plotted. The shapes of the curves of the dependence of the blood plasma clotting time on the activity of enoxaparin sodium were shown to be similar for both Enoxaparin sodium and Clexane. The Heptest method showed that Enoxaparin sodium (Technologiya Lekarstv, Russia) was comparable to the original drug Clexane (Sanofi, France).

[Palliative surgical correction of respiratory insufficiency in diffusive pulmonary emphysema]. / Palliativnaia khirurgicheskaia korrektsiia dykhatel'noi nedostatochnosti pri diffuznoi émfizeme legkikh.

AIM: To analyze early postoperative period in patients with diffuse pulmonary emphysema after palliative surgical correction of respiratory failure. MATERIAL AND METHODS: The study included 196 patients who underwent bullectomy (n=111) and surgical reduction of pulmonary volume (n=85). RESULTS AND DISCUSSION: Overall morbidity and mortality were 40.8% and 12.2% respectively. Among patients older than 60 years these values were significantly higher (58.0% and 22.6% respectively). It was shown that age over 60 years is associated with high risk of complications and mortality after excision of large and giant bulls. In patients <60 years morbidity is comparable after bullectomy and surgical reduction of pulmonary volume. CONCLUSION: Selection of patients for palliative surgical correction of respiratory failure is generally corresponded to that for lung transplantation. However, these methods should be considered complementary rather competing.

Closed Vitrification System as A Platform for Cryopreservation of Tissue Engineered Constructs.

BACKGROUND: Cryopreservation of mesenchymal stromal cells (MSCs) and MSCs-based tissue engineered constructs (TECs) is a promising strategy for regenerative medicine. OBJECTIVE: To examine vitrification system consisting of multicomponent vitreous solution, closed type container, human adult MSCs and two-step exposure procedure as a platform for cryopreservation of MSCs-based TECs. MATERIALS AND METHODS: Vitrification properties of solutions were studied by visual analysis and calorimetry. Viability (trypan blue, MTT-test), metabolic activity (Alamar Blue assay) and adhesion of cells were assessed both after exposure with vitreous solutions and following rapid cooling-thawing in standard cryovials. RESULTS: The feasibility of the vitrification system was tested on MSCs suspensions (S-MSCs) and alginate encapsulated MSCs (AE-MSCs). The minimal concentrations of cryoprotectants, which allowed avoiding ice formation during rapid cooling and rewarming comprised 10 % for dimethylsulfoxide, 20 % for ethylene glycol, 20 % for 1.2-propanediol and 0.5 M sucrose. To achieve viability and metabolic activity rates of AE-MSCs comparable to S-MSCs after vitrification the extension of the exposure time within the same vitreous solution was sufficient. After vitrification both S-MSCs and AE-MSCs retained the capacity to osteogenic and adipogenic differentiation. CONCLUSION: Data demonstrate that this vitrification system can be used as a platform for development of effective protocols for cryopreservation of MSCs-based TECs.

[Features of binding of proflavine to DNA at different DNA-ligand concentration ratios].

The binding of proflavine to calf thymus DNA has been studied using the methods of differential scanning calorimetry and spectrophotometry. It was shown that proflavine can interact with DNA by at least 3 binding modes. At high DNA-ligand concentration ratios (P/D), proflavine intercalates into both GC- and AT-sites, with a preference to GC-rich sequences. At low P/D ratios proflavine interacts with DNA by the external binding mode. From spectrophotometric concentration dependences, the parameters of complexing of proflavine with DNA were calculated. Thermodynamic parameters of DNA melting were calculated from differential scanning calorimetry data.

[Effect of freezing on cord blood serum proteins].

The effect of freezing regimes and storage temperatures on protein conformation and the spectrum of cord blood serum has been investigated. Changes in the parameters of ESR spectra of spin probes in cord blood serum after slow freezing and subsequent thawing were established, indicating protein conformational changes characterized by loosening. This fact is confirmed by an earlier process, the first stage of albumin heat denaturation, as indicated by calorimetric data. It was shown that slow cooling results in the aggregation of serum protein in which serum albumin and immunoglobulins play an important role. It was concluded that, for retaining the properties, of cord blood serum proteins, it is preferable to perform cooling at a rate not lower than 100 degrees C/min and a storage temperature of -80 degrees C and lower.

[Interaction of actinocin derivative with different poly(rC) structures].

The interaction of actinocin derivative Act III with single- and double-stranded poly(rC) has been investigated by the methods of differential scanning microcalorimetry and UV-vis absorption spectroscopy. It was shown that, after the addition of the ligand, the temperature, enthalpy and entropy of poly (rC) melting decrease. The analysis of poly(rC)-ActIII absorption spectra indicated that the conformation of polynucleotide differs from that of free poly (rC) in the presence of ActHI at pH 4.46 and pH 6.0. Using the DALSMOD optimization program, the parameters of interaction of Act III with poly (rC) were calculated. It was found that the binding constant of ActHI with double-stranded poly (rC) is essentially higher than that with the single-stranded one upon monomeric binding. On the basis of these data, we conclude that the conformation changes of the matrix are the main cause of the decrease in melting temperature and enthalpy observed by calorimetry. Possible mechanisms of interaction of actinocin derivative with poly (rC) are discussed.

Acoustic emission during cooling and heating of aqueous solutions of polyethylene glycols of molecular masses from 300 to 3000.

The object of this research is to study acoustic emissions (AE) in aqueous solutions of polyethylene glycols (PEGs) of molecular masses from 300 to 3000 during cooling at 100 degrees C/min and heating at 70 degrees C/min in the temperature range from 0 to -196 degrees C. The dependence of AE intensity on PEG concentration and molecular mass is analysed. The AE intensity correlated with the crystalline to amorphous phase ratio in the frozen system.

On phase transitions in the water-ethylene glycol system at subzero temperatures under non-isothermal conditions.

The dynamic phase diagrams of the water-ethylene glycol (EG) system have been plotted at the warming rate of 0.4 degrees C/min(-1) after cooling of samples down to -196 degrees C by quenching in liquid nitrogen or slow cooling at the rate of approximately 0.15 degrees C/min(-1). The melting of two stable eutectics at the temperatures of -42.7 degrees C and -48.7 degrees C and the metastable eutectic at -63 degrees C was observed. Hydrates 1:1 crystallized separately from ice during warming both after quenching and after slow cooling. Glass devitrification and EG:3H(2)O hydrate melting took place during warming of the samples after quenching but these thermal features were absent after slow cooling in the EG concentration range of 42.0 - 63.5 weight percent. The notions about two-stage mechanism of ice nucleation in EG aqueous solutions might be critically revised

[Functional status of cryopreserved rat liver mitochondria]. / Izuchenie funktsional'nogo sostoianiia kriokonservirovannykh mitokhondrii pecheni krysy.

Mitochondria from the rat liver have been frozen down to -196 degrees C under protection of dimethylsulfoxide, after which they were subjected to periodical increase and decrease in temperature (cycling) in the ranges of -105 degrees C to -196 degrees C or -135 degrees to -196 degrees C. There have been observed some non-lethal damages of mitochondria which were revealed in the decrease in the respiratory control and in the ADP/O ratio after the cycling. The damage rate increased with the increase of the number of temperature decrease-increase cycles. The damages were also greater in the case when the upper limit of cycling temperature was higher than the glass transition temperature of the freezing medium (Tg = -126 degrees C). The non-lethal damages of mitochondria are explained by the influence of electric fields, appearing in the frozen sample during the temperature increase or decrease.