U50,488, a kappa opioid receptor agonist, attenuates cocaine-induced increases in extracellular dopamine in the nucleus accumbens of rats.

Because an increase in extracellular levels of dopamine in the nucleus accumbens has been associated with the reinforcing effects of addictive drugs, we investigated whether U50,488, a selective kappa opioid receptor agonist, would alter cocaine-induced increases in extracellular dopamine in the nucleus accumbens using in vivo microdialysis in awake and freely moving rats. Cocaine (20 mg/kg i.p.

Duodenal ulcer.

Duodenal ulcer constitutes one component of the clinical-pathologic complex of peptic disease of the duodenum. Recent evidence suggests that this chronic process may be cured with antibiotic therapy. Radiologic evaluation provides a cost-effective approach to the selection of patients for such management.

Effects of iboga alkaloids on morphine and cocaine self-administration in rats: relationship to tremorigenic effects and to effects on dopamine release in nucleus accumbens and striatum.

Ibogaine, a naturally occurring alkaloid, has been claimed to be effective in treating addiction to opioid and stimulant drugs and has been reported to decrease morphine and cocaine self-administration in rats. The present study sought to determine if other iboga alkaloids, as well as the chemically related harmala alkaloid harmaline, would also reduce the intravenous self-administration of morphine and cocaine in rats. Because both ibogaine and harmaline induce tremors, an effect that may be causally related to neurotoxicity in the cerebellar vermis, the temorigenic activities of the other iboga alkaloids were assessed.

Neurochemical predisposition to self-administer cocaine in rats: individual differences in dopamine and its metabolites.

Using in vivo microdialysis, this study attempted to determine whether a neurochemical predisposition to self-administer cocaine could be identified. Estimated extracellular levels of dopamine and its metabolites were measured bilaterally in the mesocorticolimbic and nigrostriatal systems of naive rats that were subsequently trained to self-administer cocaine intravenously. There were several significant relationships between dopamine and dopamine metabolite (3,4-dihydroxyphenylacetic acid and homovanillic acid) levels and rates of cocaine self-administration during both acquisition and asymptotic phases of testing.

Lines of Blaschko.

The lines of Blaschko represent a pattern followed by many skin disorders. We review the clinical and histologic features of X-linked, congenital/nevoid, and acquired skin diseases that follow these lines. We also include cutaneous disorders that have a linear distribution but do not follow Blaschko's lines.

Barium studies in patients with Candida esophagitis: pseudoulcerations simulating viral esophagitis.

Objective: The purpose of this report is to describe an abnormality identified on barium studies in patients with Candida esophagitis that simulates discrete or aphthous ulceration. This finding may be misinterpreted as suggesting viral esophagitis.

Patients And Results: Between 1989 and 1993, four patients with endoscopically confirmed Candida esophagitis and no evidence of associated viral infection were treated at Hahnemann University.

Barium studies in patients with Barrett's esophagus: importance of focal areas of esophageal deformity.

Objective: I report a subtle finding of columnar metaplasia of the esophagus (Barrett's esophagus) on barium examination that to my knowledge has not been described before. The finding is a focal mural deformity associated with fixed transverse folds and minimal limitation of distensibility of the esophagus at least 4 cm proximal to the esophagogastric junction.

Materials And Methods: The abnormality was seen in four patients who had air-contrast upper gastrointestinal barium studies for evaluation of various gastrointestinal symptoms.

Selection of medical students: the Beer-Sheva perspective.

In many Western medical schools with a low attrition rate the selection of medical students represents the key hurdle for admission to the practice of medicine. The process therefore deserves careful attention. Described herein are impressions and conclusions from almost two decades' experience in selecting medical students at the Ben-Gurion University in Beer-Sheva, Israel.

Estimating extracellular concentrations of dopamine and 3,4-dihydroxyphenylacetic acid in nucleus accumbens and striatum using microdialysis: relationships between in vitro and in vivo recoveries.

It is common practice in microdialysis studies for probes to be "calibrated" in artificial CSF and in vitro recoveries determined for all substances to be measured in vivo. Dialysate concentrations of such substances are then "corrected" for in vitro recoveries to provide "estimates" of extracellular concentrations. At least for dopamine, in vitro and in vivo recoveries are significantly different and, therefore, an estimate of extracellular dopamine based on correction for in vitro recovery is likely to be erroneous.

Handling and/or saline injections alter basal and morphine-evoked changes in dopamine metabolites in the striatum and nucleus accumbens of rats.

The effect of IP saline injections on basal dopamine (DA), homovanillic acid (HVA), and dihydroxyphenylacetic acid (DOPAC), and morphine-evoked levels of DA, DOPAC, and HVA in the striatum (STR) and nucleus accumbens (NAC) of female Sprague-Dawley rats was quantified, using in vivo microdialysis. In the STR, saline injections twice daily over 3 days, then once on day 4 (2x /day group), resulted in higher basal DOPAC and HVA levels compared to unhandled rats (naive group), or rats injected with saline once daily for 4 days (1x /day group). DOPAC and HVA were greater after IP injection of 30 mg/kg morphine in the saline 2x /day group compared to the saline 1x /day and naive groups.

Effects of prenatal cocaine exposure on the nigrostriatal dopamine system: an in vivo microdialysis study in the rat.

Pregnant rats were given injections of saline (0.5 ml/kg) or cocaine (10 mg/kg, 20 mg/ml, s.c.

Noniterative compensation for the distance-dependent detector response and photon attenuation in SPECT imaging.

A filtering approach is described, which accurately compensates for the 2D distance-dependent detector response, as well as for photon attenuation in a uniform attenuating medium. The filtering method is based on the frequency distance principle (FDP) which states that points in the object at a specific source-to-detector distance provide the most significant contribution to specified frequency regions in the discrete Fourier transform (DFT) of the sinogram. By modeling the detector point spread function as a 2D Gaussian function whose width is dependent on the source-to-detector distance, a spatially variant inverse filter can be computed and applied to the 3D DFT of the set of all sinogram slices.

Changes in the nature of inpatient medical services--impact on medical education and patient care.

One hundred sequential admissions to an internal medicine department in a 765-bed teaching hospital in 1973 were compared to 100 admitted in 1987. Mean age in 1973 was 50.3 years as compared to 57.

Lateralized changes in prefrontal cortical dopamine activity induced by controllable and uncontrollable stress in the rat.

Exposure to stressors that are not controlled results in a variety of changes in behavior and in brain chemistry. Among these is the activation of dopamine-containing neuronal systems projecting to the medial prefrontal cortex (PFC), to a lesser extent the nucleus accumbens (NAC) and, in a few studies, the striatum. Previous data have shown that stressor evoked PFC activation is asymmetrical.

Pharyngography after head and neck irradiation: differentiation of postirradiation edema from recurrent tumor.

Objective: In patients previously irradiated for head and neck carcinomas, persistent soft-tissue thickening in the larynx and pharynx makes it difficult to distinguish between postirradiation edema and recurrent epidermoid carcinoma. The goal of this work was to characterize the standard double-contrast pharyngographic appearance after irradiation and to differentiate this appearance from that of recurrent or residual neoplasms.

Materials And Methods: The posttreatment pharynogograms in 43 patients treated with radiotherapy for malignant tumors of the head and neck were retrospectively reviewed.

Compassionate physicians: personality traits and prosocial attitudes.

Three groups of physicians were identified based on their compassionate behavior. Associations with personal characteristics indicate that physicians with high self-esteem are more likely than those with low self-esteem to behave in congruence with their attitudes towards people.

Local effects of ibogaine on extracellular levels of dopamine and its metabolites in nucleus accumbens and striatum: interactions with D-amphetamine.

Systemic administration of ibogaine (40 mg/kg, i.p.) has been reported to induce both acute (1-3 h) and persistent (19-20 h) changes in extracellular levels of dopamine and its metabolites in the nucleus accumbens and striatum.

14 beta-[(p-nitrocinnamoyl)amino]morphinones, 14 beta-[(p-nitrocinnamoyl)amino]-7,8-dihydromorphinones, and their codeinone analogues: synthesis and receptor activity.

A series of 14 beta-[(nitrocinnamoyl)amino]codeinones and morphinones, some of which contain a 5 beta-methyl group, were prepared from 14 beta-aminocodeinones and 14 beta-[N-(cyclopropylmethyl)-amino]norcodeinones. The affinities of the target compounds for the mu, delta, and kappa opioid receptors were determined by radiolabeled binding experiments using bovine brain membranes. An analogous series of 7,8-dihydrocodeinones and morphinones was prepared and assayed in the same systems.

Prenatal ethanol exposure alters ethanol-induced dopamine release in nucleus accumbens and striatum in male and female rats.

Using in vivo microdialysis, ethanol-induced dopamine release in nucleus accumbens and striatum was examined in adult male and female Long-Evans rats exposed prenatally to ethanol and in controls. Following dialysis, ethanol intake was measured in an operant paradigm. Control rats showed increased dopamine release in nucleus accumbens and striatum in response to 0.

Sex differences in ethanol-induced dopamine release in nucleus accumbens and in ethanol consumption in rats.

In vivo microdialysis was used to examine changes in nucleus accumbens and striatal dopamine, dihydrophenylacetic acid (DOPAC), and homovanillic acid (HVA) following acute administration of ethanol (0.0, 0.25, 0.

Dopamine release and metabolism in nucleus accumbens and striatum of morphine-tolerant and nontolerant rats.

Morphine administered at high doses produces a biphasic locomotor effect, characterized by an initial locomotor depression, followed a short time later by hyperlocomotion. Prior exposure to morphine produces tolerance to the motor-depressive effects and sensitization to the motor-activating effects of morphine. Little is known of the neurochemical changes that occur to produce tolerance and sensitization to morphine.

[Misinformation among physicians about dangers of fetal x-ray exposure].

A survey among 20 gynecologists and 86 family physicians and general practitioners revealed that only 46% (70% of the gynecologists and 41% of the others) knew that exposure of a pregnant woman to common diagnostic x-ray is not an indication for therapeutic abortion (the opinion of a consensus of experts). This lack of basic information by those who advise pregnant women points to a serious public health problem. Pregnant women are frightened, and in a sense abortions are "coerced" by increasing the unwarranted anxiety.