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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 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
High-dose vitamin E lowers urine porphyrin levels in patients affected by porphyria cutanea tarda
No full textPorphyria cutanea tarda (PCT) is a metabolic disorder of heme biosynthesis, characterized by reduced uroporphyrinogen decarboxylase (UROD) activity and increased urinary excretion of eight and seven carboxyl group porphyrins. Specific factors such as iron, alcohol and halogenated compounds further inhibit enzyme activity by generating reactive oxygen species. Antioxidant vitamin E has frequently been used to counteract oxidative stress in porphyria patients, but a number of studies have failed to detect any significant effect on porphyrin metabolism. Since the use of vitamin E in the treatment of porphyria is a debated question, it seemed of interest to administer high doses to five patients with PCT in order to evaluate the effects on urine porphyrin excretion. The patients had high urinary porphyrin excretion levels, but vitamin E significantly reduced the urinary excretion of eight carboxyl group porphyrins. This result is attributable to the increase in UROD activity caused by the vitamin, which is a known scavenger of the oxygen reactive species that interfere with the activity of the enzyme. In conclusion, this paper shows that vitamin E high doses significantly lowers the urine porphyrin excretion in studied patients affected by PCT. Copyright 2002 Elsevier Science Ltd. All rights reserve
Speckle tracking echocardiography for detection of subclinical cardiac involvement in rheumatoid arthritis
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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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 ondansetron administration on opioid withdrawal syndrome observed in rats
No full textThis study tested whether a 5-HT3 receptor antagonist could reverse the signs of precipitated opioid withdrawal. Rats were treated with either saline or morphine for 4 days. After the four days, half of the rats in each group received naloxone and half received saline. Each animal also received one of four doses of ondansetron (0, 1, 2 and 4 mg/kg i.p.). Administration of ondansetron to rats receiving naloxone after chronic morphine decreased the intensity of withdrawal signs such as increased defecation, jumping and wet-dog shakes, elevated the nociceptive threshold values which were decreased by precipitated withdrawal, but produced no change in urination, rectal temperature or salivation. The effects exhibited by ondansetron administration may be explained through interference of its 5-HT3 receptor antagonist activity with serotoninergic mechanisms involved in the regulation of these withdrawal symptoms. The use of this drug is thus suggested as a possible treatment of opioid withdrawal signs in heroin addicts
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