Multiple subcortical haemorrhages following lumbar metrizamide myelography

Summary The case is presented of a patient showing multiple subcortical haemorrhages after lumbar metrizamide myelography. This complication after intrathecally administered metrizamide contrast medium appears not to have been reported before. Several different possible explanations are proposed for the phenomena observed in this case.     

不同剂量瑞芬太尼复合靶控输注异丙酚对心脏瓣膜置换术病人气管插管时血液动力学反应的影响

目的 评价不同剂量瑞芬太尼复合靶控输注(TCI)异丙酚对心脏瓣膜置换术病人气管插管时血液动力学反应的影响.方法 拟行心脏瓣膜置换术的风湿性心脏病病人30例,随机分为3组(n=10):芬太尼组(Ⅰ组)、小剂量瑞芬太尼组(Ⅱ组)和大剂量瑞芬太尼组(Ⅲ组).麻醉诱导:Ⅰ组静脉注射芬太尼10 μg/kg,然后持续静脉输注芬太尼10 μg·kg-1·h-1;Ⅱ组和Ⅲ组静脉注射瑞芬太尼1μg/kg,然后分别持续静脉输注瑞芬太尼0.5、1.0 μg·kg-1·min-1.3组静脉注射芬太尼或瑞芬太尼后3min开始TCI异丙酚,初始血浆靶浓度为1.0 μg/ml,逐渐递增至2.0 μg/ml.静脉注射罗库溴铵0.6 mg/kg后气管插管.分别在麻醉诱导前(T0)、诱导期间血压最低值时(T1)、插管前即刻(T2)、插管后1 min(T3)、插管后2 min(T4)及插管后5 min(T5)时记录心率(HR)、平均动脉压(MAP)、中心静脉压(CVP)、肺毛细血管楔压(PCWP)、心脏指数(CI)、外周血管阻力指数(SVRI)及左室每搏功指数(LVSWI),并于上述时点测定混合静脉血氧饱和度(S(v)O2).记录诱导期间低血压及气管插管心血管反应的发生情况.结果 3组间麻醉诱导期间低血压及气管插管心血管反应的发生率差异无统计学意义(P＞0.05).与T0比较,各组T1,2时HR和MAP均降低,Ⅱ组T3时HR和MAP升高,Ⅲ组T4时MAP降低,Ⅰ组和Ⅱ组T2-4时S(v)O2升高(P＜0.05);3组间各时点CVP、PCWP、CI、LVSWI和S(v)O2差异无统计学意义(P＞0.05).结论 复合TCI异丙酚(血浆靶浓度2.0 μg/ml)时,静脉注射瑞芬太尼1 μg/kg负荷剂量后,持续静脉输注0.5 μg·kg-1·min-1麻醉诱导时血压和HR下降适度,可较好地抑制心脏瓣膜置换术病人气管插管时血液动力学反应.     

Neuropathology in non-human immunodeficiency virus-infected drug addicts: hypoxic brain damage after chronic intravenous drug abuse

Neuropathological studies were carried out on 180 human immunodeficiency virus-seronegative intravenous drug addicts. The findings in victims of acute heroin intoxication (n = 116) were congestion (99.1%), capillary engorgement (68.1%), and/or perivascular bleeding (68.1%) – hemodynamic processes attributable to toxic primary respiratory failure. In a high percentage of these cases (88%), cerebral edema was also present. In 18 cases of acute heroin intoxication who survived for periods of hours or days, the sole postmortem finding was ischemic nerve cell damage, resembling that typically seen in systemic hypoxia. Semiquantitative analysis revealed nerve cell loss in the hippocampal formation and/ or Purkinje cell layer in 26% of the 162 chronic drug abusers. By contrast, in nearly 80% of these cases, the hippocampus showed enhanced expression of glial fibrillary acid protein by astrocytes and/or a proliferation of microglia, demonstrated by CD68 expression. Since such reactive processes are produced by primary neuronal damage, it can be assumed that chronic intravenous drug abuse results in obviously ischemic nerve cell loss. This could be demonstrated in the hippocampus, but it must also occur throughout the whole brain. The demonstration of ischemic nerve cell damage and neuronal loss or secondary reactive alterations has not been described previously. Received: 31 March 1995 / Revised, accepted: 27 November 1995     

Substitution of the 5-HT1 agonist trifluoromethylphenylpiperazine (TFMPP) for the discriminative stimulus effects of ethanol: effect of training dose

The role of the ethanol training dose on the ability of the selective 5-HT¹ agonist TFMPP (m-trifluoromethylphenylpiperazine) to produce ethanol-like discriminative stimulus effects was evaluated in three groups of rats trained to discriminate 1.0 g/kg (n=5), 1.5 g/kg (n=6) or 2.0 g/kg (n=7) ethanol (IG) from water using a two-lever procedure with food reinforcement available under a fixed ratio 20 (FR 20) schedule. Ethanol generalization gradients were comparable in the three groups, indicating few potency differences in the ethanol stimulus across training dose. However, the ability of TFMPP (0.1–1.7 mg/kg; IP) to substitute for ethanol was dependent on the training dose. TFMPP resulted in partial substitution in the 1.0 g/kg group, complete substitution for 1.5 g/kg group and no substitution in the 2.0 g/kg ethanol training group. The results indicate a serotonergic component to the discriminative stimulus effects of an intermediate dose of ethanol that is not prominent as the dose of ethanol is raised. These data add further support for the hypothesis that ethanol produces a mixed discriminative cue, the components of which are not uniformly amplified when the dose of ethanol is increased.     

33 factorial design-based optimization of the formulation of nitrofurantoin microcapsules

A microcapsule form of nitrofurantoin was prepared by a simple coacervation method with carboxymethylcellulose and aluminium sulfate. 3³ factorial design was performed for three independent variables, namely, the particle size of the drug, the size of the microcapsules and the pH of the dissolution medium. The dissolution tests with the formulated microcapsules were carried out according to the United States Pharmacopeia XXII rotating basket method at pH 1.2, 5 and 7.5, which represent the pH of gastrointestinal fluids. Release data were examined kinetically and the ideal kinetic models were estimated and t _63.2 values obtained from RRSBW distribution were used in the factorial design experiment. The influence of the independent variables on the dissolution of nitrofurantoin microcapsules could be expressed as the pH of the dissolution medium > particle size of the microcapsule > particle size of nitrofurantoin. The other aim of this study was to evaluate microcapsule formulation in terms of the United States Pharmacopeia criteria with a minimum of experiments. Our findings suggest that dosage forms which comply with the pharmacopoeia criteria for dissolution can be prepared and selected by factorial design.     

The Discriminative Stimulus Properties of Acute Ethanol Withdrawal (Hangover) in Rats

Twenty male Sprague-Dawley rats were trained to discriminate pentylenetetrazole (PTZ, 15 mg/kg, intraperitoneally) from saline (SAL) under a drug discrimination procedure. Test sessions were conducted with 10 randomly selected subjects. Tests with various doses of PTZ resulted in a dose-dependent increase in the percentage of total session responses emitted on the PTZ-appropriate lever without a significant change in response rates across a wide range of test PTZ doses. Rats did not generalize the PTZ stimulus to ethanol (ETOH) up to ETOH test doses that completely suppressed responding. High acute ETOH doses (2, 3, and 4 g/kg) administered at various time points prior to discrimination test sessions engendered responding on the PTZ-appropriate level in a quantitative fashion, that was dose- and time-dependent. This acute ETOH delayed effect from these high doses replicates our previously published study using a Drug 1-Drug 2 discrimination task with Chlordiazepoxide and PTZ. More importantly, we suggest that the present behavioral assay may be a sensitive animal analogue of human "hangover" phenomena.     

Neuroexcitatory actions of Tamiflu and its carboxylate metabolite

Oseltamivir (Tamiflu) is now being stockpiled by several governments as a first line treatment for an anticipated outbreak of avian influenza caused by H5N1. However, abnormal behaviors and death associated with the use of Tamiflu have developed into a major issue in Japan where Tamiflu is often prescribed for seasonal influenza. Thus, it is critical to determine neuropsychiatric effects of oseltamivir and to establish methods for safe administration. Using juvenile rats and rat hippocampal slices, we investigated whether oseltamivir has adverse effects on the central nervous system. Systemic injection of oseltamivir (50 mg/kg i.p.) produced no change in behavior within 2 h. However, prior injection of oseltamivir significantly altered the duration of loss of lightning reflex following ethanol injection (3.3 g/kg, i.p.). Ethanol injection in the presence of oseltamivir also resulted in enhanced hypothermia. In the CA1 region of hippocampal slices, oseltamivir (100 μM) induced paired-pulse facilitation in population spikes without changes in excitatory postsynaptic potentials. Similarly, 3 μM oseltamivir carboxylate, the active metabolite of oseltamivir, facilitated neuronal firing, though the facilitation did not involve GABAergic disinhibition. Moreover, oseltamivir carboxylate produced further facilitation following administration of 60 mM ethanol. These findings indicate that oseltamivir has effects on the central nervous system, especially when combined with other agents.     

An Association Between a Microsatellite Polymorphism at the DRD5 Gene and the Liability to Substance Abuse: Pilot Study

We have conducted a population-based association study of substance abuse and a microsatellite at the dopamine D5 receptor locus (DRD5) in a sample of European–American males and females with substance dependence (SA) or without any psychiatric disorder. Overrepresentation of the most frequent allele (148 bp) was found in males in the SA group (OR = 2.2, P= .02); this finding was reproduced in females (OR = 5.4, p< .001). The difference in the frequencies of this allele between SA males and SA females was statistically significant. The genotype coded in accordance with the dose of this allele correlated with substance abuse liability in males and females (stronger in females) and with novelty seeking in females. There was no evidence of correlation between the genotypes of spouses that could be induced by assortative mating for the liability to substance abuse. The data suggest that the DRD5 locus is involved in the variation and sex dimorphism of substance abuse liability.CEDAR is a consortium between St. Francis Medical Center and the University of Pittsburgh.