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New organic nanostructures were synthesized by introducing 2-methylbenzimidazole (MBI) molecules from a melt, gas phase, or alcoholic solution into nanosized voids of borate porous glasses (PG), nanotubes of chrysotile asbestos (ChA), and mesoporous silica (MS). The incorporation of MBI into borate glasses with different pore sizes is accompanied by the appearance of several phases formed by nanocrystallites which have a MBI crystal structure, but somewhat differ in lattice parameters. The size of some crystallites significantly exceeds the size of nanopores, which indicates the presence of long-scale correlations of the crystal structure. The size of MBI nanocrystallites in ChA was close to the diameter of nanotubes ( D ~10 nm), which shows the absence of crystal structure correlations. The XRD pattern of mesoporous silica filled by MBI does not exhibit reflections caused by MBI and a presence of MBI was confirmed only by the analysis of correlation function. The incorporation of MBI molecules into matrices is observed through optical IR absorption spectroscopy (FTIR) and photoluminescence. Introducing MBI in ChA and MS is followed by the appearance of bright green photoluminescence, the spectral structure of which is analogous to MBI crystals but slightly shifted in the blue region, probably due to a quantum-size effect. The influence of MBI inclusion in PG and ChA on the permittivity, dielectric losses, conductivity, and parameters of their hopping conductivity is analyzed.

Single crystals of 2-methylbenzimidazolium perchlorate were prepared for the first time with a slow evaporation method from an aqueous solution of a mixture of 2-methylbenzimidazole (MBI) crystals and perchloric acid HClO 4 . The crystal structure was determined by single crystal X-ray diffraction (XRD) and confirmed by XRD of powder. Angle-resolved polarized Raman and Fourier-transform infrared (FTIR) absorption spectra of crystals consist of lines caused by molecular vibrations in MBI molecule and ClO 4 - tetrahedron in the region ν = 200-3500 cm -1 and lattice vibrations in the region of 0-200 cm -1 . Both XRD and Raman spectroscopy show a protonation of MBI molecule in the crystal. An analysis of ultraviolet-visible (UV-Vis) absorption spectra gives an estimation of an optical gap E g ~3.9 eV in the crystals studied. Photoluminescence spectra of MBI-perchlorate crystals consist of a number of overlapping bands with the main maximum at E photon ≅ 2.0 eV. Thermogravimetry-differential scanning calorimetry (TG-DSC) revealed the presence of two first-order phase transitions with different temperature hysteresis at temperatures above room temperature. The higher temperature transition corresponds to the melting temperature. Both phase transitions are accompanied by a strong increase in the permittivity and conductivity, especially during melting, which is similar to the effect of an ionic liquid.

Aging of a living organism is closely related to systemic metabolic changes. But due to the multilevel and network nature of metabolic pathways, it is difficult to understand these connections. Today, this problem is solved using one of the main approaches of metabolomics - untargeted metabolome profiling. The purpose of this publication is to systematize the results of metabolomic studies based on such profiling, both in animal models and in humans.

Metabolomics is one of the omics sciences, the technologies of which are widely used today in many life sciences. Its application influenced the discovery of new biomarkers of diseases, the description of biochemical processes occurring in many organisms, laid the basis for a new generation of clinical laboratory diagnostics. The purpose of this review is to show how metabolomics is represented in the studies of Russian scientists, to demonstrate the main directions and achievements of the Russian science in this field. The review also highlights the history of metabolomics, existing problems and the place of Russian metabolomics in their solution.

In the frame of the work, data on the implementation of metabolomics tests in medicine have been systematized. Based on the obtained data, a set of protocols was proposed, the sequential realization of which makes it possible to conduct a blood metabolome analysis for medical purposes. Using this analysis and the number of blood samples from healthy volunteers, a prototype of a healthy person's metabolomic image has been developed; it allows visually and digitally to assess the compliance of the human blood metabolome with the norm. At the same time, 99% of the metabolic processes reflected in the blood plasma are estimated. If abnormalities are detected, the metabolomic image allows to get the value of these deviations of metabolic processes in digital terms.

Background: The frequency of bronchopulmonary dysplasia (BPD) in preterm infants with a "ventilator-associated" pneumonia (VAP) ranges between 7 to 50%., Objective: To investigate the features of the etiological structure of neonatal pneumonia complicated by BPD, and to determine the sensitivity of pathogens to antibiotics., Methods: A retrospective chart review of 194 preterm infants with VAP, birth weight from 780 to 2820 g and gestational age from 27 to 37 weeks was conducted. A microbiological study of washings from the respiratory tract was conducted by standard qualitative and quantitative methods., Results: Respiratory tract infections caused by E. coli (with hemolytic properties), Enterococcus spp. (with hemolytic properties), Pseudomonas aeruginosa, Stenotrophomonas maltophilia, various types of mycoplasmas, Staphylococcus aureus, and Candida krusei were found 4- 13 times more frequent in preterm infants with BPD than in preterm infants without BPD and more mature infants with or without this complication. BPD developed 7- 11 times more frequent in preterm infants with prolonged VAP and change in pathogens than in preterm infants with VAP without change of agent. BPD developed 5- 7 times more frequent in preterm infants with the association of pathogens than in preterm infants with a monoinfection. Massive colonization of respiratory tract pathogens by 1- 3 days of life (lg4 colony forming units in 1 ml and above) was an unfavorable prognostic factor for the development of VAP, complicated by BPD., Conclusion: The reduction in the frequency of BPD is might be possible with timeous and adequate antibacterial therapy of VAP.

The review is devoted to pharmacometabonomics - a new branch of science focused on personalization of drug therapy through the comprehensive analysis of metabolites of patient's biological fluids. It considers the history of pharmacometabonomic, positioning to other "-omic" sciences, and system approach, realized by this science, in determination of individual therapeutic dose of the drugs and also a technical implementation of pharmacometabonomic based on direct mass spectrometry of blood plasma metabolites. Special attention is paid to a comparative analysis of pharmacometabonomics and other main approaches to personalized therapy in the clinic, such as pharmacogenetics and therapeutic drug monitoring. Finally, prospects of pharmacometabonomics applications in clinical practice were also discussed.

Optimal conditions for culturing of multipotent mesenchymal stromal cells in the presence of pooled umbilical cord blood serum were determined. It was found that umbilical cord blood serum in a concentration range of 1-10% effectively supported high viability and proliferative activity of cells with unaltered phenotype and preserved multilineage differentiation capacity. The proposed approach allows avoiding the use of xenogenic animal sera for culturing of multipotent mesenchymal stromal cells and creates prerequisites for designing and manufacturing safe cellular and/or acellular products for medical purposes.

We studied the expression of different classes of surface molecules (CD13, CD29, CD40, CD44, CD54, CD71, CD73, CD80, CD86, CD90, CD105, CD106, CD146, HLA-I, and HLA-DR) in mesenchymal stromal cells from human umbilical cord and bone marrow during co-culturing with nucleated umbilical cord blood cells. Expression of the majority of surface markers in both types of mesenchymal stromal cells was stable and did not depend on the presence of the blood cells. Significant differences were found only for cell adhesion molecules CD54 (ICAM-1) and CD106 (VCAM-1) responsible for direct cell-cell contacts with leukocytes and only for bone marrow derived cells.

Umbilical cord stroma is an easily available, convenient, and promising source of multipotent mesenchymal stromal cells for regenerative medicine. Cryogenic storage of umbilical cord tissue provides more possibilities for further isolation of multipotent mesenchymal stromal cells for autologous transplantation or scientific purposes. Here we developed a protocol for preparation of the whole umbilical cord tissue for cryogenic storage that in combination with the previously described modified method of isolation of multipotent mesenchymal stromal cells allowed us to isolate cells with high proliferative potential, typical phenotype, and preserved differentiation potencies.

We analyzed changes in cell composition of umbilical cord blood and functional activity of hematopoietic stem cells during cryogenic storage and after repeated freezing/thawing cycles. It was found that repeated freezing/thawing cycles performed according to the optimal programmable freezing protocol did not significantly affect viability and functional activity of hematopoietic stem cells. When fast freezing program was used, the cells completely lost their capacity to form colonies in semisolid medium, despite high viability parameters in the test with 7-AAD.

Extraembryonic tissues, in particular, umbilical cord stroma are promising sources of multipotent mesenchymal stromal cells for regenerative medicine. In recent years, methods for isolation of mesenchymal stromal cells from different compartments of the umbilical cords based on enzymatic disaggregation of the tissue or on tissue explants have been proposed. Here we propose a protocol of isolation of multipotent mesenchymal stromal cells from the whole umbilical cord that combines the advantages of each approach and ensures sufficient cell yield for further experimental and clinical applications. A combination of short-term incubation of tissue fragments on cold collagenase solution followed by their culturing in the form of explants significantly increased the yield of cells with high proliferative activity, typical pluripotent mesenchymal stromal cell phenotype, and preserved differentiation capacity.

Changes in cell composition and viability as well as the content and functional activity of hemopoietic progenitor cells were analyzed during long-term (up to 1 month at 4°C) storage of human umbilical cord blood cells. No significant quantitative changes in erythrocytes were found during this period. The total content and viability of leukocytes changed, which resulted in the prevalence of mononuclear cells (lymphocytes and monocytes). Analysis of functional activity of hemopoietic stem cells in semisolid culture revealed a decrease in the relative content of CFU during the first week of storage [corrected] and inability of cells to colony formation after 2 weeks.

The paper analyses the morphological and functional features of cord blood cells (CBCs) in the co-culture with multipotent mesenchymal stromal cells (MMSCs) from human adipose tissue under tissue-related oxygen. We have established that MMSCs effectively maintained viability of CBCs at different oxygen concentrations (1, 5 and 20%). According to the data obtained, the oxygen concentration affected the number of colony-forming units (CFUs) formed by CBCs in selective medium. In particular, not co-cultured CBCs the 1 and 5% O2 than at 20% O2. After co-culture with MMSCs, the CFUs numbers were similar at 1 and 20% O2 and increased by 30 at 5% O2. Tissue related O2 concentrations had an impact on the proportion of lineage-resctricted CFCs among CBCs: the number of more committed progenitors--CFU-G and CFU-M, increased, and multi and bipotent--CFU-GEMM and CFU-GM, decreased at low oxygen concentrations. This effect was more pronounced after co-culture compared to that of initial CBCs. Thus, the presence of stromal cells and tissue-related oxygen jointly and severally influenced CBCs in vitro.

A new method for the analysis of blood lipid based on direct mass spectrometry of lipophilic low molecular weight fraction of blood plasma has been considered. Such technique allows quantification of hundreds of various types of lipids and this changes existing concepts on diagnostics of lipid disorders and related diseases. The versatility and quickness of the method significantly simplify its wide use. This method is applicable for diagnostics of atherosclerosis, diabetes, cancer and other diseases. Detalization of plasma lipid composition at the molecular level by means of mass spectrometry allows to assess the effectiveness of therapy and to optimize the drug treatment of cardiovascular diseases by phospholipid preparations.

This guideline provides the diagnostic and treatment algorithm for newborns with gestational age over 35 weeks and weighing more than 1800g who has severe asphyxia in birth with the threat of severe or medium-severe hypoxic-ischemic encephalopathy.

The article describes a new therapeutic drug monitoring (TDM) method based on direct infusion of low-molecular fraction of blood into electrospray ionization source of mass spectrometer. This technique allows performing TDM of almost all drugs used in clinic. In article, the universality and high-throughput of the method, that significantly simplifies its wide application, have been shown. Moreover, the possibility of method application in most cases of drug therapy has been argued as a tool of control of drug doses, rationality of drug therapy, and the quality of the drugs themselves. In conclusion, the prospects for application of the method as primary means of improving the quality and personalization of drug therapy have been discussed.

Unlabelled: It is common knowledge that arterial hypotension is a one of most prevalent pathology of early neonatal period and it causes severe neurological complications. Purpose of the prospective randomized open study was to assess the efficacy of HES 130/0.4 (6% Voluven) as a start medicine for arterial hypotension in early neonatal period in comparison with normal saline solution (0.9% NaCl)., Materials and Methods: the study was held from January 2010 to September 2011. Newborns of the ICU with arterial hypotension on the first day of life were included into the study. Acute haemorrhage was an exclusion criterion. Routine monitoring of arterial pressure, heart rate and diuresis was carried out in all newborns. pH, pCO2, pO2 blood glucose, lactate and BE levels were measured before and after the treatment. Echocardiography, examination of regional blood flow in anterior cerebral artery, renal artery and mesenteric artery was held HES 130/0.4 (6% Voluven) and saline solution (0.9% NaCl) were used Parameters of haemostasis, biochemical and haematological analysis monitored after the solutions use. Time of arterial pressure normalization and duration of the treatment positive effect were recorded Episodes of hypotension, amount of cardiotonics per day and per 7 days and duration of cardiotonics administration were recorded as well., Results: 6% Voluven infusion both to 0.9% NaCl infusion normalizes the regional circulation. Furthermore it increases the blood pH and diuresis. Lactate level normalization occurred only after 6% Voluven infusion. There was not change of serum sodium level. Liver enzymes, C-protein, prothrombin index were same in both groups of patients. 6% Voluven use in newborns with extremely low birth weight was accompanied with increasing of creatinine level, prolongation of activated partial thromboplastin time and increasing of intraventricular hemorrhage rate. Newborns with weight over 1000 gram did not have these complications. Voluven advantage in comparison with saline solution is a decreasing of cardiotonics administration in patients with weight over 1000 gram., Conclusions: 6% Voluven is more effective than 0.9% NaCl for increasing of cardiac output, myocardial contractile ability and diuresis, normalization of liquid balance and lactate level, decreasing of cardiotonics amount. 6% Voluven can be recommended for arterial hypotension treatment in newborns with weight over 1000 gram both to normal saline solution especially in case of shock.

In repeated implantation failure, the co-culture of human embryos with somatic cells has been reported to promote the improvement of embryos quality, implantation and pregnancy rate. It was reported that feeder cells can be more beneficial to the oocyte and embryo by detoxifying the culture medium and supporting embryo development via different pathways. In this study, 432 patients, each with a minimum of three repeated implantation failures, were accepted for a prospective randomized study with or without autologous cumulus cell embryo co-culture and transfer at day 3 or day 5-6. We also investigated the expression of leukaemia inhibitor factor (LIF) and platelet activating factor receptor (PAF-R) on day 3 confluent cumulus cells. The statistic analysis of the data showed significant difference of implantation and clinical pregnancy rates between classical culture and day 3 compared with co-culture and day 5-6 transfer. The molecular analysis showed that cumulus cells express the LIF and the PAF-R genes and confirmed the possible positive role of growth factors and cytokines in early embryo development. Embryo co-culture systems with autologous cells can be beneficial in routine in vitro fertilization for embryo selection and implantation improvement. More molecular investigations need to be done to improve elucidation of the complex dialogue between the embryo and feeder cells prior to implantation and to understand the involved biological function and molecular process during embryo development.

The authentication of mammalian cell cultures and their subpopulations is of great demand in biotechnology and cell therapy. However, current techniques are either not efficient or can be very complex and expensive. Here we report a simple and straightforward approach for authentication of biological cells and their subpopulations with high speed, high throughput, low sample cost, and high sensitivity. We discovered that cell cultures treated with protease under soft, 'non-killing' conditions release fragments of cell surface proteins, whose composition is a strong characteristic of the cells. Mass spectrometric analysis of the released fragments allows a direct comparison of the produced mass spectrum with the mass spectrum of known cells. As an example, we applied this technique to verify subpopulations of human fibroblasts with different origins and which exhibit different medical characteristics., (John Wiley & Sons, Ltd)

The authors suggest a new express-method for assessment of memory and intellect in the late age. This method allows to assess not only disturbed functions but also the intact patterns of mental processes and to conduct a quantitative assessment as well as a qualitative (syndrome) analysis of mental activity changes using a Luria's structural-functional model of the brain. The method was administered to 157 subjects of young (20-30 years), old and very old age (50-90 years). The express method may be used for the detection of age impairment and differential diagnostics of memory and intellect states in different variants of normal aging, assessment of neurocognitive deficit in patients with Alzheimer's disease and mild cognitive syndrome.

Comparative electron microscopic analysis of the patterns of centriolar and cytoplasmic microtubules immunostaining for acetylated or tyrosinated alpha-tubulin was performed during the cell cycles of the mouse diploid 3T3 (A31) and virus-transformed heteroploid SV40-3T3 cell lines. It was shown that the pattern of centriole immunostaining changed during mitosis in control 3T3 (A31) cells, but not in tumorigenic SV40-3T3 cells. A sharp change in the pattern of centriole immunostaining was observed in those cell cycle periods when the protein organization of centrosome underwent changes during interphase/mitosis or mitosis/interphase transitions due to the rearrangement of microtubule system. A high level of centriole immunostaining for tyrosinated and acetylated alpha-tubulin was observed at all cell cycle stages with the exception of entering mitosis for the former and the end of mitosis for the latter.

In this study, we have examined the organization of the mitotic spindle poles in CHO-K1 cells dividing after treatment with the etoposide (1 h, 25 microM). We studied at various periods after the treatment: 1) the distribution of gamma-tubulin in mitotic cells by immunofluorescent staining; 2) the level of posttranslational modification of a-tubulin in the spindle microtubules by immunoelectron microscopy; 3) the ultrastructure of the mitotic apparatus poles by standard electron microscopy. In 48 h after the addition of the agent we identified considerable changes in the ultrastructure of poles in etoposide-treated CHO-K1 cells with bipolar and multipolar spindles. The number of centrioles increased. The centrioles were unevenly distributed among the poles, and some centrioles were not explicitly involved in the organization of mitotic spindle, furthermore they can differ in the number of outgrowing microtubules. Most centrioles were without fibrillar halo. In 48 h after the addition of etoposide, electron microscopy of cells after immunoperoxidase staining with antibodies to acetylated and tyrosinated alpha-tubulin has shown that different poles of a multipolar spindle within the same cell are stained differently for tyr-tubulin but not for acet-tubulin. Immunofluorescence staining for gamma-tubulin also points to different organization of poles in the same spindle. Our findings provide the first evidence that the pattern of immunostaning and the ultrastructure of mitotic apparatus poles differ in the cells dividing at various periods after etoposide treatment.

Etoposide (1 h, 25 microM) causes interphase arrest in CHO-K1 after which cells resume mitotic division and die due to apoptosis after a certain time period. Accumulation of apoptotically dying cells in the culture follows a gradual increase in the number ofmultipolar mitoses. Our findings provide the first evidence that the pattern of immunostaning for alpha-tubulin, acetylated alpha-tubulin and tyrosinated alpha-tubulin in cells dividing at various periods after etoposide treatment. Moreover, some parts of the multipolar mitotic spindle differ in the presence of antigenic determinants accessible to anti-tyrosinated alpha-tubulin antibodies. It is noteworthy that these abnormalities are aggravated just before the increase in the number of apoptotically died cells. Our findings also suggest that some cells pass through at least two mitotic cycles prior to a sharp increase in the number of apoptotically died cells in the cell culture.

A EMG study of the brachial muscles in 41 children with spastic paralyses of the lower extremities, weakness of the hands concomitant with a mild hypotrophy of the muscles, disturbed functions of the III, VII and vestibular nerves and satisfactory mental development revealed the following: there were signs of motoneuron excitation in the cervical part of the spinal cord (motor units at rest in a maximum muscle contraction and in an elaboration of tenden reflexes), their destruction (a decreased amplitude of potentials of volitional contraction in combination with muscle hypotrophy) and a desinhibition of spinal mechanisms. Causes of such damage may be intrauterine pathology, perinatal hypoxia, delivery complicated by an incorrect position of the foetus and a mechanical trauma in an incomplete ossification of the spine, in premature infants.

Content of organophosphorous inhibitors (with the structure RO/CH3/P/O/SC2H4SC2H5) of cholinesterase as well as their hydrophobic properties (distribution coefficient in hexan/water system) were studied in subcellular fractions of rat brain. Relative content of organophosphorous inhibitors was distinctly decreased in supermicrosomal fraction with increase of hydrophobic properties of the fraction. Nuclear and mitochondrial fractions contained the more hydrophobic substances in relatively higher amount. When homogenate of supermicrosomal fraction was incubated at 37 degrees, own brain cholinesterase was not depressed by organophosphorous inhibitors, containing in the fraction at low concentration. The phenomenon exhibits that content of free organophosphorous inhibitors is distinctly lower in the subcellular fractions studied than amount of the inhibitors, extracted with chloroform.

Studies have been made on the effect of organophosphorus inhibitors on cholinesterases (CHe) from mammals (human and rabbit erythrocytes, mice brain) and arthropods (fly, spring grain aphid, rice weevil and spider tick). Organophosphorus inhibitors were presented by dialkylthiophosphates which contained normal or branching alkyls in the phosphoryl part of their molecule and lupinine or epilupinine residue in the other part of the latter. Increasing the length of alkyl in lupinine derivatives increased their inhibitory effect with respect to mammalian CHe, but decreased it in relation to all the investigated arthropod CHe. For epilupinine derivatives, the same relationship was found with mammalian CHe, being absent in arthropod enzymes. These data indicate the existence of significant differences in spatial structure of both esterase and anionic centers of the enzyme from mammals and arthropods. In arthropod CHe, hydrophobic regions of the esterase center are less developed that in mammalian CHe. The distance between the anionic and esterase centers of CHe is presumably different in the enzymes from different species.

Hydrophobity (coefficient in distribution in the hexane water system) and the content of cholinesterase organophosphorous inhibitors (OPI) of the structure Ro (CH3) P (O) SC2H4 SC2H5 were studied in the rat brain. When the O-alkyl radical is increased hydrophobity rises and the relative content of free OPI in the brain extracted by chloroform decreases. With an increase in R from the ethyl to butyl one the ability to the additional inhibition of the brain own cholinesterase lowers due to incubation of homogenate at 37 degrees C, that evidences for an essential drop in the studied series of the free OPI fraction relative to the free OPI extracted by chloroform.

Studies have been made of the effect of organophosphorus inhibitors (OPI) containing butynilic group in the detectable part of the molecule, and of their saturated analogues on cholinesterases from different species of mammals and arthropods. In all cases without a single exception, acetylene compounds exhibited higher anticholinesterase effect than saturated ones. The value of "acetylene effect" varied to a great extent and depended on both the structure of OPI and the source of cholinesterase, these data indicating the existence of differences in the structure of the active site in cholinesterases investigated. The acetylene effect was always higher in ethylmercapto-substituted OPI than in chloride-substituted ones. Among thiophosphates, the highest (7,600) effect was found for cholinesterase of the spider mite in the case of dimethyl esters. Among thiophosphonates, exceptionally high (38,000) effect was noted for cholinesterase from the head of the domestic fly when methylthiophosphonates were compared. In this pair of compounds, the inhibitory constant k2 for the cholinesterase of the fly by acetylene derivative was equal to 1.1 . 10(9).

An investigation of dogs with removed temporal and sincipito-occipital cortical centres of the eye movements demonstrated that a number of properties of the vestibular nystagmus evoked by the rotation of the animal remain the same as they had been in this very same animal prior to the operation. These centres do not control the nature of the nystagmic movement that consists of a slow and a fast components, the combined movements of the right and left eyes, the direction of the nystagmus, the range and the nature marking the distribution of the maximal movement and of the most frequent movements during the action of the stimulus and the symmetry of the labyrinthine function. At the same time, the dissociation of the cortical centres of the eye movements brings on shortening of the vestibular post-rotational nystagmus, activation of the mechanism that monitors the rhythmic tonic deflections of the eyes, this causing diminution in the number of nystagmic eye movements and disruption in the rhythm of their movement. It also activates arbitrary movements of the eyes that occasionally turn into a spontaneous nystagmus. The abundance of arbitrary eye movements following vestibular stimulation is of frequent occurrence in children, victims of cerebral paralysis of childhood combined wit- depressed cortical function.

In the presence of organophosphorus inhibitors (OPI) AChE inhibition is initiated at a lower concentration of ACh; the plot reaction rate versus substrate concentration shows two maxima with a distinct minimum between them. It was shown that extremely mild conditions (short-term heating up to 50 degrees C; acidic or alkaline pH shift by 0.5 units; high concentrations of bivalent cations; erythrocyte storage) which do not affect substrate inhibition, remove this effect. The data obtained suggest that OPI effect is not directed to the site of AChE responsible for enzyme inhibition by ACh excess ("substrate inhibition site"), but to some other area. This results in a change in the conformation of the substrate inhibition site and a pronounced inhibition of the AChE activity takes place at lower substrate concentration.

The content and hydrophobic properties (distribution coefficient in hexan : water) of organophosphorus inhibitors OPT of the following structure--R-O (CH3)/P/O/S C2H4SC2H5 have been studied in rat brain. On enlargement of the O-alkyl radical from ethyl to isopropyl and pinacolin hydrophobecity increases from 1 to 12 and 39, while the relative content of the chloroform extractable free OPT in brain, under conditions of uniform distribution, decreases from 11--18% to 3.2%. On incubation of the homogenate at 37 degrees C the further inhibition of the specific cholinesterase of the brain indicates the presence of an absolutely free form of OPT, the amount of which is not dependent on the degree of its hydrophobicity.