Sublimation Enthalpies of Substituted Pyridine N-Oxides.

The enthalpies of sublimation of five substituted pyridine N-oxides were determined by the Knudsen effusion method with mass spectrometric control of the vapor composition within the framework of the second law of thermodynamics. The sublimation enthalpy of mono-substituted compounds 4-X-PyO depends on the nature of the substituent X and increases in the order CH3→NO2→OCH3. A difference is noted in the nature of dissociative ionization of disubstituted derivatives 2-CH3-4-NO2PyO and 3-CH3-4-NO2PyO. The relationship between the packing of molecules in crystals and the ΔH°subl values is considered.

[A new look at reactions with participation of metal-porphyrines].

Reactions ofnucleophilic substitution and enzymatic processes with participation of metal-porphyrins (MP) are considered from the point of view of Zn-tetraphenylporphin (Zn-TPhP) coordination with corresponding ligand/nucleophyl/substrate/base. Linear correlations perform between kinetic parameters of process of coordination of Zn-TPhP in chloroform (constants of stability) and reactions of nucleophilic substitution both in aqueous and organic solvents with participation ofpyridines, N-oxides ofpyridines, anilines, primary amines and oxidation of anilines by horseradish peroxidase in aqueous solutions (rate constants). Thermodynamic parameters of complexation and nucleophilic substitution mutually correlate linearly in the case of pyridines, anilines and primary amines.

Dynamics of plasma proteome during leptin-replacement therapy in genetically based leptin deficiency.

The effects of leptin-replacement therapy on the plasma proteome of three unique adults with genetically based leptin deficiency were studied longitudinally during the course of recombinant human leptin-replacement treatment. Quantitative proteomics analysis was performed in plasma samples collected during four stages: before leptin treatment was initiated, after 1.5 and 6 years of leptin-replacement treatment, and after 7 weeks of temporary interruption of leptin-replacement therapy. Of 500 proteins reliably identified and quantitated in those four stages, about 100 were differentially abundant twofold or more in one or more stages. Synchronous dynamics of abundances of about 90 proteins was observed reflecting both short- and long-term effects of leptin-replacement therapy. Pathways and processes enriched with overabundant synchronous proteins were cell adhesion, cytoskeleton remodeling, cell cycle, blood coagulation, glycolysis, and gluconeogenesis. Plausible common regulators of the above synchronous proteins were identified using transcription regulation network analysis. The generated network included two transcription factors (c-Myc and androgen receptor) that are known to activate each other through a double-positive feedback loop, which may represent a potential molecular mechanism for the long-term effects of leptin-replacement therapy. Our findings may help to elucidate the effects of leptin on insulin resistance.

Deconvolution of insulin secretion, insulin hepatic extraction post-hepatic delivery rates and sensitivity during 24-hour standardized meals: time course of glucose homeostasis in leptin replacement treatment.

Minimally invasive methodology, mathematical model, and software for analysis of glucose homeostasis by deconvolution of insulin secretion, hepatic extraction, post-hepatic delivery, and sensitivity from 24-hour standardized meals test have been developed and illustrated by the study of glucose homeostasis of a genetically based leptin-deficient patient before and after leptin replacement treatment. The only genetically leptin-deficient adult man identified in the world was treated for 24 months with recombinant methionyl human leptin. Blood was collected every 7 minutes for 24 hours, with standardized meals consumed during the 4 visits: at baseline, one-week, 18-months, and 24-months after initiation of the treatment. Concentrations of insulin, C-peptide, and plasma glucose were measured. Insulin secretion was obtained by deconvolution of C-peptide data. Hepatic insulin extraction was determined based on our modifications of the insulin kinetics model . Insulin sensitivity for each of the four meals was calculated by using the minimal glucose model approach. Hepatic extraction of insulin was the first element of glucose homeostasis to respond to leptin replacement treatment and increased 2-fold after one week of treatment. Insulin secretion and delivery rates decreased more than 2-fold and insulin sensitivity increased 10-fold after 24 months of treatment. Computer programs for analysis of 24-hour insulin secretion, extraction, delivery, and action are available upon request.

Experimental study of kinematic focusing. Comparison of electroinjection and sequential injection determination of copper.

The recently predicted phenomenon of kinematic focusing was studied experimentally using copper ions and EDTA as reactants. Kinematic focusing occurs, in electroinjection analysis, when the detected reaction product moves at the same rate as the reagent present in excess. Thus, reaction product accumulates without dispersion at the front of the excess reagent. Cu-EDTA(2-) complex was observed at 254 nm to form an exceptionally sharp peak as the front of the EDTA zone passed by the detector. The concentrating effect of kinematic focusing was quantified by electroinjection of premixed Cu-EDTA(2-). Sensitivity was compared to that of sequential injection analysis using a 1 cm optical pathlength. Sensitivity was highest in the electroinjection mode, in spite of its 120 mum capillary pathlength, due to kinematic focusing.

Hydrodynamics and mass transfer of the coaxial jet mixer in flow injection analysis.

A coaxial jet mixer that was previously proposed for rapid and efficient mixing under laminar flow conditions has been studied both theoretically and experimentally. A mathematical model that consists of a set of Navie-Stokes equations that determine the flow velocities and three diffusion-convection reaction equations that determine the reactant and product concentrations has been developed. Equations are solved with the help of finite difference techniques for different flow conditions. The quality of sample and reagent mixing is characterized by the mean product concentration and the amount of product produced. Theoretical results are compared with experimental ones for the mixing of bromothymol blue (a pH indicator) in the outer capillary with NaOH in the inner capillary of the jet mixer.

Electroinjection analysis. The introduction of a new variant of flow-injection analysis and comparison with electrophoretically-mediated microanalysis.

A new method of mixing sample and reagent due to the difference in their electrophoretic mobilities is introduced. Unlike electrophoretically-mediated microanalysis, sample and reagent are injected from the opposite ends of a capillary tube. This method is compared with electrophoretically-mediated microanalysis. Experiments are performed showing the possibilities of this new method.

[The use of ocular drug films of propolis in the sequelae of ophthalmic herpes]. / Primenenie glaznykh lekarstvennykh plenok propolisa pri posledstviiakh oftal'mogerpesa.

There was studied the therapeutic efficiency of ocular medical propolis films (OMF) in 35 patients with postherpetic trophic keratitis and in 20 with postherpetic nebula. OMF were applied behind the lower eyelid at bedtime during 10-15 days. All the patients endured the propolis films well. OMF accelerated the cornea epithelization. Epitheliopathy and micropoint edema of cornea epithelium rapidly disappeared. Time of patients recovery reduced nearly twice (P,001) in comparison with the control group--from 14.1 to 7.6 days. On the average their visual acuity increased in two times--from 0.12 to 0.27 (P > 0.001).

On the mathematical model of flow injection analysis-II. The second order chemical reaction in a straight tube.

The mathematical model of flow injection analysis (FIA) for fast second-order chemical reaction in a straight tube is presented. The sample and reagent are initially premixed and the analytical solution for the detection output, i.e. the integral of the product of reaction concentration over the tube cross-section is given. The optimization of FIA is discussed. It is proposed to put the detector in the real FIA systems immediately after the point where the sample and reagent are satisfactorily mixed.

Investigation of the electroosmotic flow effect on the efficiency of capillary electrophoresis.

The influence of the electroosmotic flow profile on the efficiency and resolution of capillary electrophoresis is studied. The mathematical model is formulated and the set of equations is solved numerically. The results of the analysis are applicable to a wide range of buffer concentrations and capillary diameters. The temperature dependence of electrophoretic mobility, viscosity and thermal conductivity and the dependence of electrical conductivity on temperature and ion concentration in the double layer are taken into account. It is shown that there exists a region of buffer concentrations and capillary diameters where the influence of the electroosmotic flow profile on the efficiency and resolution is much greater than that of the temperature dependence of the electrophoretic mobility. The results are especially essential for small buffer concentrations or capillary diameters comparable with the double electrical layer thickness.

[Characteristics of recovery process in kidney tubule epithelium of white rats with advanced mercuric chloride-induced necrotic nephrosis]. / Osobennosti vosstanovleniia épiteliia kanal'tsev pochki beloi krysy v pozdnie sroki sulemovogo nekronefroza.

Paraffin and semithin sections were used to study the peculiarities of recovery process in kidney tubules of white rats at various intervals (3 days to 5 months). Koss reaction for evaluation of calcium saline level was used after subcutaneous injection of large doses of sublimate (0.6 mg/100 g of b.w.). The study revealed the expressed destruction of tubules to be followed by rapid (3 days after nephrotoxin injection) calcification of cellular detritus.

[Changes in the nucleoli of epithelial cells of the kidney tubules in mercuric chloride-induced experimental kidney tubular necrosis]. / Izmeneniia iadrushek épitelial'nykh kletok kanal'tsev pri sulemovom nekronefroze v éksperimente.

Electron-microscopic studies of epithelial cells of uric tubules in white rat kidneys after i.m. injections of mercury dichloride (0.4 mg/100 of body weight) given every 24, 48 and 72 hours showed the affected epithelial cells to have nonspecific changes in tubule ultrastructure, i.e. dissociation and segregation of tubule components as well as degranulation, fragmentation and hypertrophy. The dissociation of nucleolus components is followed by the damage of an essential part of cell mitochondrial apparatus and becomes irreversible. In some damaged cells degranulation is accompanied by the nucleolus decay into separate solid fragments formed of fibrous tissue. The enlargement of nucleolus fragments in the absence of proribosomes speaks in favour of the depression of proribosome formation process while the ability to synthesize p-RNA in comparatively slight.

[The isolation of tick-borne encephalitis virus strains and the determination of the scope of immune stratification among the population and the domestic animals on the northern Russian plain]. / Izoliatsiia shtammov virusa kleshchevogo éntsefalita i opredelenie velichiny immunnoi prosloiki sredi naseleniia i domashnykh zhivotnykh na severe Russkoi ravniny.

Between 1986 and 1987 the authors conducted virological survey of 689 Ixodes persulcatus and 420 mouse-like and insectivorous rodents at the territory of Arkhangelsk Province and the Republic of Komi. A total of 8 strains of tick-borne encephalitis virus were isolated. Out of them 3 strains were isolated from small mammalians (2 from Clethrionomys glareolus, 1 from Microtus oeconomus) at the southeastern areas of Arkhangelsk Province within the middle taiga subarea, 5 strains were isolated from I. persulcatus (the rate of infection was 1.25 per cent) gathered in the southeastern Komi within the southern margins of the middle taiga subarea. PHAT investigation of the sera (2064 human, 656 cow and 171 dear specimens) evidenced almost the absence of immunity among the studied populations of the tundra and forest tundra zones. Certain positive samples observed in the northern taiga region could be explained by the infection gained in areas situated more to the south. Among the middle taiga human populations the immunity reached 4.9 per cent.

[Correlations of intracellular and cellular regeneration of the epithelium of the kidney tubules in necronephrosis]. / Sootnoshenie vnutrikletochnoi i kletochnoi regeneratsii épiteliia mochevykh kanal'tsev pochki pri nekronefroze.

The study of radioautographs in ultrathin and semithin sections extracted from animal tissues and following the impulsive as well as long-term injection of 3H-thymidine was made. Intracellular regeneration processes (external cell membrane synthesis, DNA reparation, restoration of the lost albumin-synthesizing complex and cytoskeleton) turned to develop in proximal canals of epithelial cells. The processes were aimed at the liquidation of distortions preventing cell from entering mitosis.

[Isolation of viruses of antigenic complexes of California encephalitis and Bunyamwera (Bunyaviridae, Bunuavirus) from mosquitoes in northeast Asia]. / Izoliatsiia virusov antigennykh kompleksov Kaliforniiskogo éntsefalita i bun'iamvera (Bunyaviridae, Bunuavirus) iz komarov na severo-vostoke aziatskogo kontinenta.

Studies in suckling mice and by direct solid-phase enzyme immunoassay were carried out with 111,1 thousand Aedes mosquitoes collected in July, 1986, in tundra, forest-tundra, and northern taiga of Kamchatka region and Chukotka autonomous district of Magadan region (North-Pacific natural area within 69 degrees-53 degrees North and 156 degrees-177 degrees East). Eleven strains were isolated of which 7 were classified as members of the California encephalitis complex (Tahyna-like strains) and 4 as members of the Bunyamwera complex (Batai-like strains). According to electron-microscopic studies of 2 strains (one from each antigenic complex), both were classified as belonging to the family of Bunyaviridae. Strains of both complexes were isolated in all landscape zones examined--tundra, forest-tundra, northern taiga. Virus-neutralizing antibodies to them were found in human and reindeer sera also in all the landscape zones, to Tahyna virus in 11%-61%, to Batain virus in 2%-6% blood specimens. No antibody to Uukuniemi virus was found.

[Electron microscopic-radioautographic study of RNA synthesis in the epithelial cells of the kidney urinary tubules of white rats in corrosive sublimate poisoning]. / Elektronno-radioavtograficheskoe issledovanie sinteza RNK v kletkakh épiteliia mochevykh kanal'tsev pochki belykh krys pri otravlenii sulemoi.

Radioautographic study of ultrathin selections of proximal white rat renal canals labeled with 3H-uridine revealed diffuse transition of peripheral and paranuclear heterochromatin to be observed in nuclei of undamaged epithelia cells and those affected by partial necrosis in case of sublimate nephrosis. Nucleus degranulation as well as decrease in its size accompanied by inhibition of RNA synthesis is also observed. Nucleus reparation being observed 48 hours after subcutaneous injection of 0.4/0.1 kg corrosive sublimate in some cells and characterized by the appearance of granular component as well as the increase of nucleolar vacuole count is usually revealed in case of decondensation form of peripheral and paranuclear chromatin in the enlarged nuclei.