Studies were carried out into the effects of monoclonal antibodies to protein A3G7, which is associated with the differentiation of cerebellar and hippocampal neurons, on the development, retention, and reproduction o...
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The purpose of this paper is to examine and report on studies that relate mercury levels in human tissues to the presence of dental amalgams, giving special attention to autopsy studies. Until recently, there have bee...
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The purpose of this paper is to examine and report on studies that relate mercury levels in human tissues to the presence of dental amalgams, giving special attention to autopsy studies. Until recently, there have been few published studies examining the relationship between dental amalgams and tissue mercury levels. Improved and highly sensitive tissue analysis techniques have made it possible to measure elements in the concentration range of parts per billion. The fact that mercury can be absorbed and reach toxic levels in human tissues makes any and all exposure to that element of scientific interest. Dental amalgams have long been believed to be of little significance as contributors to the overall body burden of mercury, because the elemental form of mercury is rapidly consumed in the setting reaction of the restoration. Studies showing measurable elemental mercury vapor release from dental amalgams have raised renewed concern about amalgam safety. Mercury vapor absorption occurs through the lungs, with about 80% of the inhaled vapor being absorbed by the lungs and rapidly entering the bloodstream. Following distribution by blood circulation, mercury can enter and remain in certain tissues for longer periods of time, since the half-life of excretion is prolonged. Two of the primary target organs of concern are the central nervous system and kidneys.
Numerous investigations have been reporting the involvement of GM1 ganglioside in central nervous system development and memory formation. The effects of neonatal treatment with GM1 ganglioside on the performance of a...
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Numerous investigations have been reporting the involvement of GM1 ganglioside in central nervous system development and memory formation. The effects of neonatal treatment with GM1 ganglioside on the performance of adult rats in a plus-maze discriminative avoidance task and old rats in a step-down passive avoidance task were investigated. Rats were injected subcutaneously from day 3 to 15 after birth with 10 mg/kg GM1 or saline. GM1 treatment did not modify indicative landmarks of physical and motor development. Behavioural tasks were carried out when the animals were 4 (discriminative avoidance) or 24 (passive avoidance) months old. Discriminative avoidance conditioning was performed in a modified elevated plus-maze. During the training session, the animals received aversive stimulation (light and hot air blow) in one of the enclosed arms. Tests were performed 7, 14 and 21 days after conditioning (tests 1, 2 and 3), in the absence of the aversive stimulation. In all tests, GM1-treated animals spent less time in the aversive arm than in the non-aversive enclosed arm. Control animals, however, spent a shorter time in the aversive arm only in tests 1 and 2. Passive avoidance conditioning was performed in an acrylic box with a grid floor, that was partially covered by an inclined platform. Animals were placed on the platform and received a 0,5 mA foot shock when stepped down. A test was performed 48 hr later. Latency to step down presented by GM1-treated animals was significantly higher in the test session, whereas no significant increase in latency to step down was found for control animals. The results suggest a possible action of GM1 on the maturation of the central nervous system that persists during adulthood and ageing.
The acute toxicity, the oxygen consumption, the action on guinea pig ileum preparation, on heart strips and on frog flexor reflexes of 3-methyl-4-nitro-furoxan, are reported. The results of the present researches poin...
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The acute toxicity, the oxygen consumption, the action on guinea pig ileum preparation, on heart strips and on frog flexor reflexes of 3-methyl-4-nitro-furoxan, are reported. The results of the present researches point out that the toxicity of the studied compound is rather high compared to its antibacterial activity. On the contrary the depressive action of 3-methyl-4-nitro-furoxan on spinal reflexes seems of some interest. Gasco and coworkers (Gasco and Coll. 1973)have recently suggested for the methylnitrofuroxan, obtained by Beherend's method (Beherend and Schmitz 1893), the structure ( I ) of 3-methyl-4-nitro derivative. It was found (Bianco and Coll. 1973) that this compound has antibacterial activities. In the present paper we refer the results of experiments made to evaluate some pharmacological properties of 3-methyl-4-nitro-furoxan. Quantities of 3-methyl4-nitro-furoxan necessary for the pharmacological experimentation were resynthesized for us in the “Istituto di Chimica Farmaceutica e Tossicologica” (Torino).
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