Oral chloral hydrate vs. intranasal midazolam for sedation during computerized tomography.
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We conducted this single blind randomized clinical trial to compare the efficacy and safety of oral chloral hydrate and intranasal midazolam for induction of sedation for computerized tomography scan of brain in children. Participants aged 1-10 years (n=60) were randomized to receive 100 mg/kg chloral hydrate orally with intra nasal normal saline OR intranasal midazolam 0.2 mg/kg with oral normal saline. Adequate sedation (Ramsay sedation score of four) was obtained and CT scan completed successfully in 76.7% of chloral hydrate group and in 40% of midazolam group (P=0.004). No significant difference was seen for side effects frequency between the two drugs (10% in chloral hydrate, 3.3% in midazolam group; P=0.34). We conclude that oral chloral hydrate can be considered as a safe and effective drug for sedation in children undergoing CT scan of brain. (+info)
Effects of different anesthetics on oscillations in the rat olfactory bulb.
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Different types of oscillations in the olfactory bulb (OB), including theta (1 to 4 and 5 to 12 Hz), beta (13 to 30 Hz), and gamma oscillations (31 to 64 and 65 to 90 Hz), are important in olfactory information processing and olfactory-related functions and have been investigated extensively in recent decades. The awake and anesthetized states, 2 different brain conditions, are used widely in electrophysiologic studies of OB. Chloral hydrate, pentobarbital, and urethane are commonly used anesthetics in these studies. However, the influence of these anesthetics on the oscillations has not been reported. In the present study, we recorded the local field potential (LFP) in the OB of rats that were freely moving or anesthetized with these agents. Chloral hydrate and pentobarbital had similar effects: they slightly affected the power of theta oscillations; significantly increased the power of beta oscillations; significantly decreased the power of gamma oscillations, and showed similar recovery of gamma oscillations. Urethane had very different effects: it significantly increased oscillations at 1 to 4 Hz but decreased those at 5 to 12 Hz, decreased beta and gamma oscillations, and showed no overt recovery in gamma oscillations. These results provide experimental evidence of different effects of various anesthetics on OB oscillations and suggest that the choice of anesthetic should consider the experimental application. (+info)
Use of nonradioactive 2-deoxyglucose to study compartmentation of brain glucose metabolism and rapid regional changes in rate.
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A method is presented for measuring rapid changes in the rate of glucose phosphorylation in mouse brain with nonradioactive 2-deoxyglucose (DG). After times as short as 1 min after DG injection, the mouse is frozen rapidly, and selected brain regions are analyzed enzymatically for DG, 2-deoxyglucose 6-phosphate (DG6P), and glucose. The rate of glucose phosphorylation can be directly calculated from the rate of change in DG6P, the average levels of DG and glucose, and a constant derived from direct comparison of the rate of changes in glucose and DG6P after decapitation. Experiments with large brain samples provided evidence for a 2% per min loss of DG6P and at least two compartments differing in their rates of glucose metabolism, one rapidly entered by DG with glucose phosphorylation almost double that of average brain and another more slowly entered with a much lower phosphorylation rate. The method is illustrated by changes in phosphorylation within 2 min after injection of a convulsant or an anesthetic and over a 48-min time course with and without anesthesia. The sensitivity of the analytical methods can be amplified as much as desired by enzymatic cycling. Consequently, the method is applicable to very small brain samples. Examples are given for regions with volumes of 5 x 10(-4) microliters, but studies with samples as small as single large cell bodies are feasible. (+info)
Lipid peroxidation in isolated hepatocytes.
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Intracellular lipid peroxidation was initiated by the addition of ADP-complexed ferric iron to isolated rat hepatocytes and the reaction monitored by the thiobarbituric acid method or by measurement of the formation of conjugated dienes. Both the production of malondialdehyde (thiobarbituric-acid-reacting substances) and of conjugated dienes was dependent, on the ADP-Fe-3+ concentration in a dose-related fashion. Malondialdehyde formation stopped spontaneously within 20 min after the initiation of the reaction and the plateau reached was also related to the ADP-Fe-3+ concentration. Control experiments revealed that more than 90% of the malondialdehyde accumulating during the incubation period could be ascribed to intracellular production. The cellular NADPH/NADP+ ratio was always high and only slightly decreased upon ADP-Fe-3+-induced lipid peroxidation which, however, was associated with a marked decrease in the cellular glutathione concentration. The rate of accumulation of malondialdehyde as well as the final level reached during ADP-Fe-3+-initiated lipid peroxidation was increased by the addition of chloral hydrate. This apparent stimulatory effect could, however, be ascribed to the inhibition of the mitochondrial oxidation of the malondialdehyde formed during cellular lipid peroxidation, thus allowing more malondialdehyde to accumulate during the process. ADP-Fe-3+-induced cellular lipid peroxidation was associated with a decrease in the concentration of glutathione. Also, lowering of the intracellular glutathione level by the addition of diethyl maleate or by simply preincubating the hepatocytes (up to 50 min) promoted the ADP-Fe-3+ malondialdehyde production and formation of conjugated dienes. Furthermore, when cellular glutathione concentration had been lowered by preincubation of the hepatocytes, significant malondialdehyde production could be observed even at ADP-Fe-3+ concentrations which were too low to induce measurable lipid peroxidation in fresh hepatocytes. It is thus concluded that glutathione has an important role in the cell defence against lipid peroxidation and suggested that the isolated hepatocytes provide a suitable experimental model system for the characterization of this and other possible cellular defence mechanisms and how they are affected by the nutritional status of the donor animal. (+info)
Stability evaluation of 7 % chloral hydrate syrup contained in mono and multi-dose bottles under room and refrigeration conditions.
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