1,721,098 research outputs found
Quantitative evaluation of opioid withdrawal signs in rats repeatedly treated with morphine and injected with naloxone, in the absence or presence of the antiabstinence agent clonidine
No full textAn opioid withdrawal syndrome was induced in rats by repeated morphine administration and final naloxone injection. The withdrawal causes alteration of several physiological signs. The aim of the study was to describe a quantitative opioid abstinence syndrome to validate the methodology by utilizing clonidine, a well-known antiwithdrawal agent, and propose the procedure for the screening of antiabstinence drugs. In particular, rats were treated with saline, morphine, naloxone, morphine and naloxone and four doses of clonidine (0, 0.04, 0.1, and 0.25 mg/kg orally). In rats repeatedly exposed to morphine and then injected with naloxone, signs like excretion of feces and urine, salivation, behavioral jumping and wet dog shakes, rectal temperature, and pain threshold have been observed. Consequently, the objective symptoms observed in morphine plus naloxone-treated animals have been taken as markers of opioid withdrawal. These factors have been quantitatively measured and grouped to form a standardized procedure of opioid abstinence syndrome. In addition, it is possible to observe that the antiabstinence drug clonidine exerted effects on modified physiological signs appearing in morphine-dependent rats treated with naloxone, like fecal excretion, levels of rectal temperature, latency times, salivation as well as jumping behavior. The effects exerted by clonidine in this procedure and in other methods are compared and appear to be similar. In addition, comparative observations referring to both the previous methods and the present procedure related to the type of signs studied, the modality of evaluation, and suppressive activity exerted by the antiwithdrawal agent, clonidine, are performed: the greater accuracy of the proposed method becomes apparent. Thus, this experimental model, validated by the antiabstinence agent clonidine, is proposed as a useful screen for drugs affecting opioid withdrawal syndrome
A New Multi-Domain Algorithm for the Spectral Solution of the Incompressible Navier-Stokes Equations
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Effects of administration of phentonium bromide on opioid withdrawal syndrome in rats
No full textThis study has tested whether phentonium bromide, a quaternary ammonium anti-muscarinic agent, could reverse the signs of precipitated opioid withdrawal. Rats were treated with either saline or morphine for 4 days, after which half the rats received naloxone and half saline. Each animal also received one of four doses of phentonium bromide (0, 1, 3 and 9 mg kg(-1), i.p.). Administration of phentonium bromide in rats receiving naloxone after chronic morphine treatment reduced the intensity of withdrawal signs such as increased defecation or micturition, salivation and wet-dog shakes, and elevated the nociceptive threshold values. The effects of administration of phentonium bromide might result from its anti-muscarinic activity interfering peripherally with the mechanisms involved in the regulation of the withdrawal symptoms. The use of this drug is thus suggested as a possible means of controlling some of the signs observed during the acute phase of opioid withdrawal in heroin addicts
Effects of alpha-lipoic acid administration on plasma glucose levels, total malondialdehyde values and withdrawal signs in rats treated with morphine or morphine plus naloxone
No full textMorphine (CAS 57-27-2) administration or its removal induces alterations in glucose levels and oxidative status or behaviour signs, which may be hypothetically closely related; if this is correct, controlling glucose changes may lead to modifications in peroxide levels and in behaviour profile. It therefore seems important to rind a drug able to control alterations of glucose metabolism, peroxide generation and behaviour symptoms in morphine or morphine withdrawal animals. This paper describes the effects of morphine or morphine plus naloxone (CAS 51481-60-8) on the plasma levels of glucose, malondialdehyde (MDA) (CAS 100683-54-3) and behavioural signs in rats treated or not with alpha-lipoic acid (CAS 1077-28-7), known to interfere with glucose and peroxide levels.The administration of morphine or its removal by naloxone alters plasma glucose levels, increases MDA values, and also affects signs such as pain threshold values, fecal excretion and jumping behaviour.The injection of alpha-lipoic acid decreases glycemia in rats treated with morphine or morphine plus naloxone. This result may be due to the capacity of alpha-lipoic acid to facilitate glucose transport and its utilization. The administration of alpha-lipoic acid to rats given morphine or morphine plus naloxone lowers total MDA levels because of its peroxide scavenging capacity. In animals injected with morphine plus naloxone, which show altered pain thresholds, high fecal excretion and jumping behaviour, treatment with alpha-lipoic acid increases latency times, decreases fecal excretion and reduces jumping. These effects can be attributed to the capacity of alpha-lipoic acid to interfere with mediators or peroxides involved in the modified behaviour. The glycemia levels, MDA values and behavioural signs seem to be interconnected in the reported experiments. The administration of alpha-lipoic acid is demonstrated to control the alterations in plasma glucose levels, peroxide values or behavioural profile in animals receiving morphine or morphine plus naloxone
Effects of carbamazepine treatment on pain threshold values and brain serotonin levels in rats
No full textThe administration of carbamazepine to rats caused a significant increase in pain threshold values. Furthermore, treatment with carbamazepine lowered the concentration of tryptophan bound to plasma proteins and elevated the brain serotonin values. The high brain serotonin levels, observed in carbamazepine-treated rats, are probably attributable to an increased availability of brain tryptophan, since this amino acid has been substantially removed from the plasma protein compartment by carbamazepine treatment, which exhibits a high binding capacity to plasma proteins. The analgesic effects caused by carbamazepine administration have been attributed to increased levels of brain serotonin which is involved in the control of pain transmission
Effects of tizanidine administration on precipitated opioid withdrawal signs in rats
No full textAn opioid withdrawal syndrome was precipitated by naloxone administration in rats treated with morphine. The withdrawal caused alteration of several physiological signs. The aim of the study was to investigate whether the altered physiological profiles were modified by utilising tizanidine, an alpha 2 adrenergic receptor agonist which is capable of affecting faecal and urinary excretion, rectal temperature, pain threshold levels and salivation. To induce an opioid withdrawal syndrome, morphine was administered in three daily intraperitoneal injections for four days at doses of 9, 16 and 25 mg/kg (1st day), 25, 25 and 50 mg/kg (2nd day), 50, 50 and 50 mg/kg (3rd day) and 50, 50 and 100 mg/kg (4th day): naloxone was injected (30 mg/kg) i.p. 180 min after the last morphine injection. Tizanidine was administered orally at 0.17, 0.35 and 0.7 mg/kg, 60 min after the last morphine injection. Signs such as faecal and urine excretion, rectal temperature and latency times to thermal stimulus, salivation, jumping and wet dog shakes were affected in different ways by morphine, naloxone, tizanidine and by the combination of these agents. Notably, the administration of tizanidine in rats receiving morphine and naloxone decreased the intensity of certain withdrawal symptoms, including altered excretion of faeces and urine, salivation and wet dog shake behavior. Body temperature levels and nociceptive threshold values were also modified. The effects caused by tizanidine administration may be due to its alpha 2 receptor agonist activity interfering with a mechanism involved in the regulation of these previously mentioned withdrawal symptoms. Thus, the use of this drug may be indicated as a possible control of the acute phase of opioid withdrawal in heroin addicts
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Effects exerted by otilonium bromide administration on precipitated opioid withdrawal syndrome in rats
No full textAn opioid withdrawal syndrome was induced in rats by repeated morphine administration and final naloxone injection. The withdrawal causes alteration of several physiological signs. The aim of the study was to prevent the altered physiological profiles by utilising otilonium bromide. Morphine was administered in three daily i.p. injections for 4 days at doses of 9, 16 and 25 mg/kg (1st day), 25, 25 and 50 mg/kg (2nd day), 50, 50 and 50 mg/kg (3rd day) and 50, 50 and 100 mg/kg (4th day). Naloxone was injected (30 mg/kg) i.p. 180 min after the last morphine injection. Otilonium bromide was administered orally at 0, 2, 4 and 8 mg/kg, 120 min before the naloxone administration. Signs like faecal and urine excretion, rectal temperature and pain threshold levels, salivation, jumping and wet dog shakes were affected in different ways. Notably the administration of otilonium bromide in rats receiving morphine together with naloxone decreased the intensity of certain withdrawal symptoms, such as excretion of faeces, wet dog shake behaviour, and elevated the nociceptive threshold values. The effects exhibited by otilonium bromide administration may be explained through its calcium antagonist activity interfering with a mechanism involved in the regulation of these previously mentioned withdrawal symptoms. The use of this drug is thus suggested as a possible control of some acute opioid withdrawal signs in heroin addicts
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