Monitoring the level of radioactive contamination of surfaces by sources of gamma-radiation in departments of radionuclide diagnosis

Oncology Research Center, Russian Academy of Medical Sciences, Moscow. Translated from Meditsinskaya Tekhnika, No. 6, pp. 9–10, November–December, 1992.     

Possible involvement of nitric oxide in the pathogenesis of experimental convulsions of various genesis

The content of nitric oxide in convulsions of different genesis is assessed by measuring the formation of paramagnetic mononitrosyl iron complexes with diethylthiocarbamate by electron paramagnetic resonance. A 3- to 4-fold increase in the content of these complexes is found in the brain of rats with thiosemicarbazide- or N-methyl-DL-aspartate-induced seizures in comparison with control animals. A similar increase in the brain NO content was observed in maximum electrical stimulation of metrazol-induced convulsions. These changes were accompanied by elevation of secondary lipid peroxidation products. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 125, No. 1, pp. 26–29, January, 1998     

Reversal of granulocyte adherence to nylon fibers using local anesthetic agents: possible application to filtration leukapheresis

The effects of the cationic anesthetic agents tetracaine and lidocaine on granulocyte function, morphology, and adherence to nylon fibers were studied in an attempt to improve current methods of granulocyte collection by filtration leukapheresis (FL). When dissolved in acid- citrate-dextrose (ACD) plasma, these drugs significantly increased granulocyte elution from the fibers in a dose-related fashion. Granulocytes exposed to tetracaine and lidocaine remained more than 95% viable, retained normal bactericidal capacity after the drugs were washed from the cells, and had preserved membrane integrity, as evidenced by the normal ultrastructural appearance of tetracaine- exposed cells and an absence of leakage of lysozyme or lactic dehydrogenase. Granulocytes eluted with the anesthetic agents were rounded in shape with a reduction in the number of filopodial cytoplasmic projections and a relative absence of cytoplasmic vacuolization when compared to granulocytes eluted with ACD plasma alone. Dose-related inhibition of phagocytosis and adherence, which was largely reversible after washing the granulocytes, was noted. Greater than 95% of the lidocaine could be removed from the eluate with a single centrifugation and resuspension, indicating that granulocytes prepared by FL with anesthetic-enhanced elution could be potentially transfusable.     

Platelets inhibit the induction of nitric oxide synthesis by interleukin-1 beta in vascular smooth muscle cells

We have investigated the role of platelets in regulating the hemostatic and vasomotor properties of vascular smooth muscle. Experiments were performed to examine the effect of the releasate from activated platelets on the production of nitric oxide from interleukin-1 beta (IL- 1 beta)-treated cultured rat aortic smooth muscle cells. Treatment of vascular smooth muscle cells with IL-1 beta resulted in significant accumulation of nitrite in the culture media and in marked elevation of intracellular cyclic guanosine monophosphate (GMP) levels. The releasate from collagen-aggregated platelets blocked the IL-1 beta- mediated production of nitrite and the accumulation of cyclic GMP in smooth muscle cells in a platelet number-dependent manner. In functional assays, the perfusates from columns containing IL-1 beta- treated smooth muscle cells relaxed detector blood vessels without endothelium and the addition of IL-1 beta-treated smooth muscle cells to suspensions of platelets inhibited their thrombin-induced aggregation. The simultaneous treatment of smooth muscle cells with IL- 1 beta and the platelet releasate abolished both the vasorelaxing activities of the perfusates and the inhibition of platelet aggregation. Platelet releasates treated with a neutralizing antibody to platelet-derived growth factor (PDGF) failed to block IL-1 beta- induced nitric oxide production by the smooth muscle cells, as measured by both biochemical and functional assays. The platelet releasate from a patient with gray platelet syndrome likewise failed to block IL-1 beta-induced nitrite release by smooth muscle cells. These results demonstrate that platelets downregulate the production of nitric oxide by IL-1 beta-treated vascular smooth muscle cells through the release of PDGF. This effect may represent a novel mechanism by which platelets regulate vasomotor tone and thrombus formation at sites of vascular injury.     

The relationship between the anxiolytic action of selank and the level of serotonin in brain structures during the modeling of alcohol abstinence in rats

We studied the in vivo effects of the peptide anxiolytic selank (0.3 mg/kg) on the behavioral parameters of the syndrome of alcohol withdrawal and the neurochemical indices of the serotonergic system in the brain structures in ex vivo experiments in outbred rats with a preference for a 10% solution of ethanol. We found that a single administration of selank eliminates the anxious response in the elevated plus maze at 48 h after the withdrawal of ethanol and increases the time spent in the open arms and the number of entries into the open arms. Using HPLC, we showed that selank prevents an increase in the serotonin level in the frontal cortex, hypothalamus, and amygdala, which may be related to a decrease in the synthesis of serotonin. The data we obtained indicate that selank has anxiolytic activity under conditions of alcohol abstinence, which suggests that the sphere of its use in clinical practice may be widened.     

Targeted Transport as a Promising Method of Drug Delivery to the Central Nervous System (Review)

Pharmaceutical Chemistry Journal - Targeted transport systems for drug delivery to the central nervous system (CNS) are reviewed. A modern classification of dosage forms according to generation and...     

The effects of irradiation by 12C carbon ions on monoamine exchange in several rat brain structures

Rats were irradiated with carbon ions (¹²C) in a Nuklotron accelerator. The irradiation dose was 1 Gy, the energy of the ions was 500 MeV/nuclon, and the linear energy transmission (LET) was 10.6 keV/micron. The animals were decapitated 1 day after irradiation. We isolated the prefrontal cortex, nucleus accumbens, hypothalamus, hippocampus, and striatum, where we determined the concentrations of monoamines and their metabolites. Strong changes were observed in three structures, viz., the prefrontal cortex, nucleus accumbens, and hippocampus. However, significant changes were found in the prefrontal cortex and weaker changes were seen in the nucleus accumbens, whereas changes were insignificant in the hippocampus. This reaction may be related to the fact that the animals were examined on the 2nd day after irradiation. It was shown that an increase in the interval between irradiation and examination of animals results in enhancement of the effects of radiation treatment. The experiments revealed the high sensitivity and reactivity of the prefrontal cortex, which we relate to the key role of this structure in vitally critical processes of behavior.     

Modelling of the processes controlling medical property reserves

Basing on the study of contents of medical logistics modern system the principles for modelling of the processes controlling the medical property reserves in the troops and stores were developed. The developed methodology has allowed to define the optimal sizes of reserves and to establish the dependence between the troops' medical property provision and the efficiency of medical care and treatment rendered the casualties and patients.