[Molecular and clinical aspects of the effect of cytidyndiphosphocholine on cognitive functions]

OBJECTIVE

Systematization of the array of publications on cytidyldiphosphocholine (CDP-choline).

MATERIAL AND METHODS

Systematic computer analysis of all currently available publications on CDP-choline (1750 publications in PUBMED) using the topological theory of big data analysis.

RESULTS

CDP-choline is essential for acetylcholine biosynthesis, phospholipid metabolism, and DNA methylation. The article describes the effects of CDP-choline on acetylcholinergic and other types of neurotransmission, anti-inflammatory, neuroprotective and neurotrophic effects of CDP-choline. Also, the paper presents the effects of the molecule on lipid metabolism and gene expression within the post-genomic paradigm (in particular, an increase in the expression of nicotinic and muscarinic acetylcholine receptors). The results of fundamental and clinical studies of CDP-choline in the treatment of cognitive impairments associated with cerebral ischemia and neurodegeneration are presented.

CONCLUSION

The pharmacological effects of CDP-choline are mediated through multiple molecular mechanisms that contribute to the nootropic action of this molecule.

Ion-temperature determination with a baffled Langmuir probe

An electrostatic Langmuir probe for real-time measurements of parameters in magnetized plasma is tested in fully ionized, barium, Q-machine plasma. The small-diameter, long-length, tungsten wire sensor, i.e., the probe tip, oriented with its cylindrical axis perpendicular to the magnetic field (B), is partially shielded by ceramic baffles, or masks, that form sensor-access slots between the baffles. Adjusting the azimuthal orientation of the slots, by rotating the probe about its cylindrical axis, changes the fraction of proximity gyro-orbiting electrons, relative to the fraction of proximity gyro-orbiting ions, that can access the recessed sensor along the magnetic field. Thus, the ratio between the electron and ion saturation currents, I_e ^sat and I_i ^sat, can be adjusted without having affected the probe bias voltage V_b. When optimally shielded (I_e ^sat/I_i ^sat=1), accurate, real-time measurements of space potential V_s can be acquired. When maximally shielded (I_e ^sat/I_i ^sat≪1), accurate, real-time measurements of ion temperature T_i can be acquired. Subtracting the floating potential V_f of an optimally shielded baffled probe from V_f of a maximally shielded baffled probe yields T_i (and its fluctuation phase) in real time.

Investigation of the anticonvulsant and remyelinating potential of dexketoprofen on a rat model of primary generalized seizures

Objective: to investigate the effect of dexketoprofen on the severity of seizures on a rat model of primary generalized seizures caused by thiosemicarbazide; to evaluate the neuroprotective effect of the drug.

Material and methods. The investigation was conducted on 72 male albino rats weighing 200–300 g. The animals were given dexketoprofen and/or comparison drugs (gabapentin, sodium valproate) for 5 days, after which the seizure model was reproduced. The effects of the drugs were evaluated from a set of neurological tests and the results of a histopathological examination of the brain.

Results and discussion. Dexketoprofen reduced the severity, duration, and number of primary generalized seizures and potentiated the anticonvulsant effects of gabapentin and sodium valproate. Histopathological and morphometric examinations of the rat brain showed that dexketoprofen inhibited the formation of irreversible neuronal changes (27.2%; control, 55.7%), by transferring them into reversible changes (47.7%; control, 21.8%).

Conclusion. The investigation made it possible to conclude that dexketoprofen had a moderate neuroprotective effect neurologically and morphometrically verified.

[INFLUENCE OF NITRIC OXIDE AND ALPHA-TOCOPHEROL ON STRUCTURAL CHANGES IN PLACENTA DURING VIOLATION OF UTEROPLACENTAL CIRCULATION IN WHITE RATS]

We have studied the effect of nitric oxide and alpha-tocopherol on morphological changes in the placenta of white rats during pregnancy complicated by disorders of the uterine and placental circulation. Violation of the uteroplacental circulation was reproduced by the method of M. M. Vartanova (1984). In white rats with violated uteroplacental blood circulation, the use of L-arginine methyl ester compensates for disturbances of the fetoplacental blood flow. It is established that an increase in nitric oxide and the inhibition of free radical processes in the placenta of experimental animals under conditions of artificially created pathology of pregnancy belong to pathogenetic rather than sanogenetic factors.

[Effect of nitric oxide on the morphology of the placenta and the activity of placental macrophages during uncomplicated pregnancy in the experiment]

OBJECTIVE

To study the effects of nitric oxide (NO) on the morphology of the placenta and the activity of placental macrophages during uncomplicated pregnancy in albino rats.

MATERIAL AND METHODS

The animals were divided into 3 groups. Group included animals with uncomplicated pregnancy; Group 2 was given drinking water containing 0.2% sodium nitrate on day 1 of pregnancy; Group 3 was intramuscularly injected with the NO synthesis inhibitor Nw-nitro-L-arginine methyl ester (L-NAME) in a dose of 10 mg/kg on day 1 of pregnancy. The central portion of hematoxylin- and eosin-stained placentas was morphologically examined. The activity of placental macrophages was assessed by incubating them with autologous erythrocytes.

RESULTS

Pathological examinations of the placentas reveal that when sodium nitrite and L-NAME enter the animal body, structural changes in the placental show that there are maternal and placental circulatory disorders concurrent with dystrophic and destructive processes.

CONCLUSION

The activity of placental macrophages in the examined groups is diametrically opposite.

Control of current and voltage oscillations in a short dc discharge making use of external auxiliary electrode

A dc discharge with a hot cathode is subject to current and voltage plasma oscillations, which have deleterious effects on its operation. The oscillations can be inhibited by installing an auxiliary electrode, placed outside of anode. By collecting a modest current through a small opening in anode, we show that the discharge becomes stable, in a certain pressure range. This method of avoiding current oscillations can be used, for example, for high current stabilizers.

Magnetically insulated baffled probe for real-time monitoring of equilibrium and fluctuating values of space potentials, electron and ion temperatures, and densities

By restricting the electron-collection area of a cold Langmuir probe compared to the ion-collection area, the probe floating potential can become equal to the space potential, and thus conveniently monitored, rather than to a value shifted from the space potential by an electron-temperature-dependent offset, i.e., the case with an equal-collection-area probe. This design goal is achieved by combining an ambient magnetic field in the plasma with baffles, or shields, on the probe, resulting in species-selective magnetic insulation of the probe collection area. This permits the elimination of electron current to the probe by further adjustment of magnetic insulation which results in an ion-temperature-dependent offset when the probe is electrically floating. Subtracting the floating potential of two magnetically insulated baffled probes, each with a different degree of magnetic insulation, enables the electron or ion temperature to be measured in real time.

Anomalously high near-wall sheath potential drop in a plasma with nonlocal fast electrons

It is demonstrated for the first time that the presence of a small number of fast, nonlocal electrons can dramatically change the thickness of and electric field in the near-wall sheath. Even if the density of the nonlocal fast group, , is much less than the density of the bulk electrons, n(b) (n(f) approximately 10(-5) n(b)), the near-wall potential can increase dramatically resulting in a comparable increase in the sheath thickness. Because of this low fractional density, the average energy (electron temperature ) of all electrons is little changed from that of the bulk, yet the near-wall potential drop can increase to tens of T(e)/e. More importantly, due to the nonlocal nature of this group of electrons, the near-wall sheath potential is found to be independent of and is determined only by the energy of the fast group.

Modification of a nonlocal electron energy distribution in a bounded plasma

It is demonstrated experimentally, in a pulsed discharge, that it is possible to modify the "tail" of a nonlocal electron energy distribution (EED) without significantly changing the electron density and temperature (mean energy). The EED tail is modified by changing the potential of a small portion of the plasma boundary and/or by changing the volume creation rate of electrons with energies in the range of the tail of the EED. The discussed effects are a direct result of the nonlocal nature of the EED and have applications to a number of basic research issues associated with discharges under nonequilibrium conditions. As an example, we discuss the possibility of utilizing these methods to measure electron impact excitation cross sections from the metastable states of atoms, which are difficult to measure by other means. The experiments have been conducted in an argon and argon-nitrogen pulsed rf inductively coupled plasma discharge.

Measurements of anomalous particle and energy fluxes in a magnetized plasma

Electrostatic probe measurements of low frequency plasma fluctuations and anomalous particle and energy flux densities in a magnetized plasma are presented. A method allowing the simultaneous recording of instantaneous electric field, electron density, and temperature is invoked. The method is applied to flux density measurements in a weakly ionized, low beta plasma created in a toroidal device without magnetic rotational transform. It is also used to identify modes belonging to different dispersion branches and to obtain the dispersion relations for these modes. For the plasma states studied, the phase velocities and the cross phase between the electron density and electric field agree with those predicted from a local, linear stability analysis for electrostatic flute modes and drift waves. The instability threshold, however, is one order of magnitude higher than predicted by theory for unsheared flow. The fluxes measured are consistent with the estimated ionization rate.

[Use of ultrasound in the study of the hip joints of fetuses during different periods of intrauterine development]

There has been investigated a hundred of women (aged 25-36 years) with aggravated obstetric-gynecologic anamnesis with wrong fetus position, familial predisposition for congenital hip dislocation and hip joint dysplasia. Fetuses were investigated at the "Toshiba" ultrasonography apparatus by a sensor with frequency of 5 mHz. Investigation of fetus hip joint in different terms of prenatal development has demonstrated that the joints were presented mainly by immature forms (11 a type) though at later terms of prenatal development there were present mature joints as well (1 a type). Ultrasonographic investigation permits to determine and measure the diameter of cartilaginous head of femur, evaluate its relation to cotyloid cavity, measure the center of the head ossification. The most intensive growth of the head occurs at 26-38 weeks of prenatal development. Hip joint stability can only be evaluated at later term of prenatal development.