[Catalytic properties of lipase adsorbed on nanocarbon-containing mesoporous silica in esterification and transesterification reactions].

Nanocarbon-containing mesoporous silica covered with a varying amounts of nanostructured carbon of different morphologies were used as supports to immobilize Thermomyces lanuginosus lipase. The catalytic properties of the prepared biocatalysts were studied in both the transesterification of vegetable (linseed) oil in the presence of ethyl acetate and the esterification of the fatty acid (capric C10:0) in the presence of secondary (isopropyl or isoamyl) alcohols. The physico-chemical characteristics, such as the amount of adsorbed lipase, its specific activity, and the dependence of the activity and stability of the prepared biocatalysts on the support type were evaluated. The Michaelis-Menten kinetics was studied in the esterification of capric acid with isoamyl alcohol. The prepared biocatalysts were shown to retain up to 90% activity for >1000 h in the synthesis of isoamyl caprate. The half-time of the biocatalysts inactivation in the transesterification of linseed oil was found to be more than 700 h at 40°C.

[Recombinant strain producing thermostable lipase from Thermomyces lanuginosus immobilized into nanocarbon silica matrices and properties of the prepared biocatalyzers].

Multicomponent composite biocatalyzers with lipolytic activity have been studied. These biocatalyzers were prepared through the immobilization of a recombinant producer strain of thermostable lipase from Thermomyces lanuginosus into SiO2 xerogel, which contains a nanocarbon component, i.e., multilayered carbon nanotubes with varying diameters, and also bulblike structured carbon nanospheres ("nanobulb"). The properties of lipase were studied both in cell suspensions of a recombinant producer strain constructed based on E. coli BL21(DE3) and in the immobilized state with regard to the structure and dispersibility of the nanocarbon component used in the composition of the biocatalyzers. It was shown that the recombinant intracellular lipase exerted its activity in a reaction of tributirin hydrolysis on average comprising 50 U/mg of dried cells and had a high level of thermostability. Upon heating in olive oil at 100 degrees C, the inactivation constant and the period of semi-inactivation comprised 6 x 10(-3) min(-1) and 2 h, respectively, exceeding by one order the thermostability of lipase in a buffer solution. Biocatalyzers that contained aggregated "thick" nanotubes with a diameter of 20-22 nm had the maximum initial activity-250 U/g.

[Comparative analysis of morphofunctional indicators of peritoneal macrophages in mice of the cancer line A/SN and white outbred mice].

A study of the functional state of peritoneal macrophages was conducted of white outbred mice (W/o) which were resistant to cancer pathology as well as the mice of the A/sn line prone to development of cancer diseases. It was reveald that due to induction of aseptic inflammation ( induced by starch administration), chemotaxis of macrophages of the oncological line was 2.5-3 times reduced and capacity to adhesion was 1.5-2 times lower than capacity of macrophages of the control group (W/o). The paint on F-actin of cytoskeleton in cells showed that cells of the control group form filopodia as a result of adhesion to the substrate, during intercellular contacts as well as during macrophage incubation with retinoic acid. Macrophages A/sn can form pseudopodia when exposed to retinoic acid. Macrophages of both groups of mice were shown to be producer of endonucleases. The same activity of these enzymes was provided by the number of cells which was 1.5-2 times fewer in mice of the A/sn line.

[Criptogenic epilepsy: a phenocopy of idiopathic epilepsy?].

We studied 18 patients with generalized tonic-clonic seizures. The signs of idiopathic epilepsy were as following: normal physical and neurological status, seizures of awakenings, peculiarity of circadian rhythms ("owls"), hyper synchronous type of EEG. The EEG and MRI study revealed insignificant epileptiform or structural changes. The authors consider these findings as possible phenocopies of idiopathic epilepsy.

[Immobilization of a recombinant strain producing glucose isomerase on SiO2-xerogel and properties of prepared biocatalysts].

An original method of immobilization of nongrowing microorganism cells on xerogel of silicon dioxide containing insoluble hydroxyl compounds of cobalt(III) has been developed. A recombinant strain producing glucose isomerase has been constructed on the basis of Escherichia coli with the use of a gene of Arthrobacter nicotianae. It was revealed that glucose isomerase activity and stability of biocatalysts prepared on the basis of the recombinant E. coli strain was 3-5 times greater compared with the biocatalysts prepared with the use of the donor strain A. nicotianae. Under conditions of continuous hydrolysis of 3 M fructose at 62-65 degrees C in a fixed bed reactor, time of half-inactivation of the biocatalysts prepared from the recombinant strain and A. nicotianae was -60 and -25 days, respectively.

[A study of the catalytic properties of the nitrile hydratase immobilized on aluminum oxides and carbon-containing adsorbents].

The nitrile hydratase isolated from Rhodococcus ruber strain gt1, displaying a high nitrile hydratase activity, was immobilized on unmodified aluminum oxides and carbon-containing adsorbents, including the carbon carrier Sibunit. The activity and operational stability of the immobilized nitrile hydratase were studied in the reaction of acrylonitrile transformation into acrylamide. It was demonstrated that an increase in the carbon content in the carrier led to an increase in the amount of adsorbed enzyme and, concurrently, to a decrease in its activity. The nitrile hydratase immobilized on Sibunit and carbon-containing aluminum alpha-oxide having a "crust" structure displayed the highest operational stability in acrylonitrile hydration. It was shown that the thermostability of adsorbed nitrile hydratase increased by one order of magnitude.

[Catalytical properties of Arthrobacter nicotianae cells, a producer of glucose isomerase, immobilized in xerogel of silicium dioxide].

Arthrobacter nicotinanae cells, producers of glucose isomerase, were immobilized in xerogel of silicium dioxide, and properties of the resulted heterogeneous biocatalysts were investigated in the process of isomerization of monosaccharide (glucose and fructose). The glucose isomerase activity of the resulted biocatalysts was shown to be 10 U/g, on average, taking into account the loss of the activity upon the immobilization, which amounted to 50% of the cell activity in suspension. The rate of the fructose isomerization increased linearly in the range of 55-80 degrees C with the temperature coefficient 1.3. The biocatalysts were stable in this range; they were rapidly inactivated, however, at increasing temperature. The half-inactivation time was six to seven h and five min or less at 80 degrees C and 85 degrees C, respectively. The half-inactivation time of heterogeneous biocatalysts was 50-90 h in the periodic process of isomerization of 2 M monosaccharides at 60 degrees C in the presence of the immobilized Arthrobacter nicotinanae cells.

[Glucose isomerase activity in suspension of Arthrobacter nicotianae cells and adsorption immobilization of the microorganisms on inorganic carriers].

Kinetics of monosaccharide isomerization has been studied in suspensions of intact, non-growing Arthrobacter nicotianae cells. Under the conditions of the study, glucose and fructose were isomerized at the same maximum rate of 700 micromol/min per 1 g dried cells, which increased with temperature (the dependence was linear at 60-80 degrees C). The proposed means of adsorption immobilization of A. nicotianae cells involve inorganic carriers differing in macrostructure, chemical nature, and surface characteristics. Biocatalysts obtained by adsorbing the cells of A. nicotianae on carbon-containing foam ceramics in the coarse of submerged cultivation were relatively stable and retained original activity (catalysis of monosaccharide isomerization) throughout 14 h of use at 70 degrees C. Maximum glucose isomerase activity (2 micromol/min per 1 g) was observed with biocatalysts prepared by adsorption of non-growing A. nicotianae cells to the macroporous carbon-mineral carrier Sapropel and subsequent drying of the cell suspension together with the carrier.

[Catalytic properties of glucoamylase immobilized on the synthetic carbon material Sibunit].

Glucoamylase (commercial preparation Glucavamorin) was immobilized by sorption on a carbon support Sibunit. Starch saccharification by the resulting biocatalyst (dextrin hydrolysis) was studied. Investigation of the effect of adsorptional immobilization on kinetic parameters of glucoamylase, including the rate constant of thermal inactivation, showed that immobilization of Glucavamorin on Sibunit resulted in a thousandfold increase in glucoamylase stability in comparison with the dissolved enzyme. Presence of the substrate (dextrins) in the reaction mixture had a considerable stabilizing effect. Increase in dextrin concentration increases the thermostability of the immobilized enzyme. The overall factor of glucoamylase stabilization adsorbed on Sibunit with the presence of 53% dextrin solutions in comparison with the dissolved enzyme approximated 10(5). The biocatalyst for starch saccharification made on the base of Subunit-adsorbed Glucavamorin had a high operational stability. Its half-inactivation time at 60 degrees C exceeded 30 days.

[Role of Mg2+-dependent alkaline endodnaase of blood serum in tumorigenesis in A/smail mice].

An enzymoassay of levels of Mg2+-dependent alkaline endoDNAase of protein spectrum of blood serum of noninbred albino mice by SDS-electrophoresis in 10% PAAG established a fairly high heterogeneity of the enzyme. The variety of alkaline endoDNAases must be due to the limited proteolysis of their high-molecular precursor by specific proteases as described in the literature. No alkaline endoDNAase activity was identified by analysis of 10-150 kDa protein spectrum in A/smail line mice without ascites hepatoma. It was detected (pH 8.3) in the 25-45 kDa range on day 10 after tumor transplantation. Considering the gravity of disease (pre-lethal stage), on day 10, it was suggested that the level be accounted for by decay of diseased cells. The lack or extremely low level of endoDNAase activity in original blood serum expressed a mechanism of enhancing sensitivity to tumor cell effects. In mice bearing ascites hepatoma, the enzyme levels (pH 8.3) were much higher on day 10. DNAase activity (pH 7.5) was not induced in response to the heterogenous DNA. Our data point to possible defects in the induction of Mg2+-dependent alkaline endoDNAases (pH 8.3) and DNAses (pH 7.5) as well as their role in raising sensitivity to transplantable ascites hepatoma.

[Immobilized glucoamylase: A biocatalyst of dextrin hydrolysis].

Heterogeneous biocatalysts of starch conversion based on glucoamylase and carbon-containing carriers were obtained, and their biocatalytic properties in enzymatic hydrolysis of corn dextrins were studied. It was shown that the morphology of the surface carbon layer of carriers markedly affected the properties of biocatalysts. Glucoamylase that was immobilized by adsorption on the surface of carriers covered with a layer of catalytic fibrous or pyrolytic carbon had the maximum enzymatic activity and stability, whereas the biocatalysts prepared on the basis of carriers that had no carbon layer or were covered with graphite-like surface carbon had a low activity and stability.

[Immobilized yeast membranes as biocatalysts for sucrose inversion].

Yeast membranes were obtained by autolysis of various strains with relatively high invertase activity. Heterogeneous biocatalysts for sucrose inversion were made of the yeast membranes and granulated carbon-containing supports made of common natural materials: expanded clay aggregate (ECA), sapropel, and lignin. The properties of these biocatalysts were studied. It was shown that the biocatalyst activity and stability of the immobilized yeast membranes increased with reference to the initial ECA, independent of the structure of the carbon layer synthesized on the support surface. Heterogeneous biocatalysts prepared by adsorption of yeast membranes on sapropel had the greatest activity and stability, whereas lignin-based biocatalysts were relatively unstable.

[Dynamic of DNAse activity induction in serum of normal animals after heterogeneous DNA injection and in hereditary pathology]. / Dinamika induktsii DNKaznoi aktivnosti v syvorotke krovi zhivotnykh pri vvedenii geterogennoi DNK v norme i pri nasleduemoi patologii.

Studies of reactions in animals with hereditary diseases (Sapphire minks highly sensitive to Aleutian disease virus, ADV; CBA mice with 60-70% incidence of tumors; AKR mice with 90% incidence of leukemia) showed that serum DNAse activity in these animals dropped after injection of a foreign heterogeneous DNA and remained decreased during 72 h. By contrast, serum DNAse activity considerably and persistently increased after injection of DNA in Standard minks resistant to ADV, C57BI/6J mice with 1% tumor incidence, and random-bred albino mice. Presumably the capacity of standard minks to react to a foreign heterogeneous DNA by increase of DNAse activity ensures their resistance to DNA-containing ADV, while incapacity of Sapphire minks to respond to DNA by DNAse activity induction makes them sensitive to ADV. A similar relationship between the capacity to react to DNA by changes in serum DNAse activity and capacity to inherit a disease was detected in mouse strains.

[Time course of serum nuclease activity in mice infected with Plasmodium berghei]. / Dinamika nukleaznoi aktivnosti v syvorotke krovi myshei pri infitsirovanii ikh Plasmodium berghei.

The present paper shows that murine serum nuclease activity increases following P.berghei infection. DNA activity begins increasing just 48 hours after infection. Following 78 hours, it achieves the maximum, by exceeding the baseline level by 6 times. Then DNA activity starts decreasing and following 94 hours after infection it is just thrice higher than the baseline. Serum RNA activity shows only 30% increases 72 hours after infection and returns to the baseline following 94 hours. Microscopic monitoring indicates that only single malaria causative agents appear in the red blood cells in this period. The peak increases in nuclease activities after P.berghei infection are assumed to be associated with the induction of serum infection.

Time course of serum nuclease activity in mice infected with plasmodium malariae.

Time course of DNase and RNase activities in the sera of random-bred mice infected with Plasmodium malariae (chloroquine-sensitive strain H) was studied. Similarly to viral infection, infection with a protozoa eukaryotic parasite was accompanied by increased DNAse and RNAse activities, though Plasmodium malariae biologically differes from viruses.

[Photosensitive epilepsy]. / Fotosensitivnaia épilepsiia.

Photosensitive epilepsy (PE) is the most frequent form of reflex epilepsy. Authors picked out two PE forms based on the analysis of the 16 own observations. The first form is PE with environmental factors of the process' provocation, which is characterised by genuine character of disease, pre- and pubertal period of its beginning, considerable prevalence of males among the patients, rare generalized tonic and clonic fits and favorable prognosis. The second form of PE is significantly rarer PE form -with self-induction of the fits. It is characterized by the beginning of the disease in preschool period, even sex distribution, quite frequent evaluated organic damages of brain, nonconvulsive fits, non-efficiency of antiepileptic drugs. The mechanisms of pathogenesis and the ways of fits' prophylaxis were discussed.

[A positive effect from a combination of gonadotropin with antiepileptic preparations in patients with hypogonadism and epileptic seizures]. / Polozhitel'nyi éffekt ot sochetaniia gonadotropina s antiépilepticheskimi preparatami u bol'nykh s gipogonadizmom i épilepticheskimi pripadkami.

The paper reports a case of combination of hypogonadism with epileptic fits. This presentation confirms the importance of endocrine factors and their probable influence on epileptic activity.

[Infection by influenza virus induces production of nucleases by fibroblasts]. / Infitsirovanie virusom grippa indutsiruet produktsiiu nukleaz fibroblastami.

The stability of oligodeoxyribonucleotides and activity of DNAses and RNAses in chicken fibroblasts and in the cells infected by influenza virus have been investigated. It was found that viral infection results in an increase of nucleolytic activity in cells. The fact should be taken into account when planning experiments with antisense oligonucleotides and virus infected cells.

Epoxidation of propene by microbial cells immobilized on inorhanic supports.

Immobilization of gas-utilizing microorganism strains (Mycobacteria, Rhodococcus, methane-utilizers) on inorganic supports based on alumina, silicates, and carbon was carried out to develop heterogeneous biocatalysts for the biotechnologic processes, including the process of propene epoxidation. Adsorption ability of these microorganisms, biocatalytic properties of resting and immobilized bacterial cells, and effect of immobilization techniques on biocatalysis were studied. An approach of double immobilization using inorganic materials (supports and gel) was proposed as simple, universal, and available method to immobilize bacterial cells, resulting in a higher retention (up to 100%) of cells' enzymatic activity and enhanced stability.