An experimental study of the possibilities of using pentoxifylline for the prevention of cancer at different sites

Three models of cancerogenesis were used to test the anti-cancerogenic effects of pentoxiphylline. In female rats, breast adenocarcinoma was induced by intramammary injections of N-methyl-N-nitrosourea (MNU) or colonic and rectal adenocarcinomas by intrarectal instillations of MNU. In female mice, squamous cell carcinomas of the cervix uteri and vagina were induced by intravaginal applications of 7,12-dimethyl-benz(a) anthracene (DMBA). Pentoxifylline was given with drinking water at a concentration of 500 mg/l long at the stage of carcinogenesis promotion/progression. Pentoxifylline exerted a strong inhibitory effect on the development of mammary tumors and a moderate inhibitory effect on the development of colonic and rectal tumors induced by MNU in rats. However, the drug did not affect the development of cervical and vaginal tumors caused by DMBA in mice.     

Mathematical simulation of the viscous properties of concentrated suspensions

A mathematical model for calculating the viscous properties of concentrated suspensions characterized by particle sizes of 30 to 800 µm), solids volume fractions of 1 to 70 vol %, different particle-size distributions, and a shear-rate range of 0.16 to 437 s^?1, which can describe the time evolution of the properties, is proposed. The model can be applied to calculating the viscous properties of catalyst oxide pastes, particulate-filled polymeric pastes, and the like.     

A technique for acoustic-emission testing of the wheel pairs of a freight-car carriage

A testing technique developed for determining the acceptance levels of different inspected zones of a wheel pair is considered. It has been shown that the acceptance levels are individual for different inspected zones and are set on the basis of the statistical data obtained during the tests of wheel pairs containing flaws detected beforehand. A test record sheet containing coordinates of flaws and comments on their hazard is issued during automated acoustic-emission testing of the wheel pairs of a freight-car carriage.     

The microsurgical treatment of large and giant aneurysms of the internal carotid artery located parasphenoidally

Internal carotid aneurysms in the ophthalmic area presents a challenge in cerebrovascular neurosurgery. The study was undertaken to provide evidence for the application of intravascular aspiration during direct surgical interventions and to outline their variants used at the N. N. Burdenko Institute of Neurosurgery. The study included 4 (3 females and 1 male) patients with large and giant internal carotid aneurysms of parasphenoidal site who were treated at the Institute. Clipping of the aneurysmal neck was made by employing intravascular blood aspiration from the aneurysm. The technique proved to be effective in proximal monitoring the carotid artery at surgery. It substantially reduced aneurysmal blood flow and wall tension, thus favouring aneurysmal dissection to make clipping.     

Generating operator for discrete Chrestenson functions

Problems of Information Transmission - We study the structure and properties of and a construction algorithm for a cyclic operator whose orbit consists of discrete Chrestenson functions arranged as...     

Effect of moditen-depot therapy on the duration and quality of remissions in schizophrenia patients

The authors studied the effectiveness of out-patient treatment by Moditen-Deppt of 128 schizophrenic patients. A comparison of the previous remissions appearing during usual pharmacotherapy and remissions seen during Moditen-Depot treatment depicted statistically significant differences, indicating a distinct prevention of exacerbations due to this preparation, an increase in the duration and improved quality of remissions. Such improved remissions were expressed in lesser severity, in a decrease of psychopathological disturbances, changes qualified as a "mollification of a defect" and an improvement of some socio-clinical indices.     

Glutamate dehydrogenase activity in the structures of the rabbit brain limbic system

The activity of glutamate dehydrogenase (EC 1.41.1.3) is studied in homogenates and subcellular fractions of five limbic structures: regio superior, regio inferior of hippocampus, fascia dentata, septum and corpora mamillaria. The lowest activity of the enzyme is found in regio superior of hippocampus. 80% of the total enzyme activity of primary fractions is found in "crude" mitochondria. After centrifugation of the latter within the linear sucrose density gradient the distribution of the enzume activity is similar for different structures and the highest activity is found in the region of sucrose molarity from 1.44 up to 1.50 M which corresponds to the mitochondria distribution region. 50% of the total found activity is in the fraction enriched by mitochondria, 30% is in the fraction enriched by nerve endings with the high activity of glutamate decarboxylase. It was found for different fractions that 1 mM of ADF with 0.2 mM NAD-H+ produces about 10-fold increase in the enzyme activity. Pyridoxal-5'-phosphate inhibits the enzyme from inactivation. The results are discussed in connection with the possible role of pyridoxal-5'-phosphate in regulation of the glutamate dehydrogenase activity in vivo.