Concomitant cellular reactions in optic nerve siderosis existing for 30 years

Metal foreign bodies located in the optic nerve are a rare clinical picture and sooner or later often associated with vision loss. We report on a patient who had a foreign body in the optic nerve for 30 years. Histochemical analysis of the optic nerve after the requisite enucleation with complete functional loss of the eye revealed amazing results. Even 30 years after entry of the foreign body into the optic nerve neuronal structures with organized axons surrounded by cytoblasts, glial cells, and immunocompetent cells still remoined. These findings hold out hope and may serve as the starting point for regenerative medicine to potentially restore neuronal function.     

Bromocriptine increased operant responding for high fat food but decreased chow intake in both obesity-prone and resistant rats

Dopamine (DA) and DA D? receptors (D2R) have been implicated in obesity and are thought to be involved in the rewarding properties of food. Osborne-Mendel (OM) rats are susceptible to diet induced obesity (DIO) while S5B/P (S5B) rats are resistant when given a high-fat diet. Here we hypothesized that the two strains would differ in high-fat food self-administration (FSA) and that the D2R agonist bromocriptine (BC) would differently affect their behavior. Ad-libitum fed OM and S5B/P rats were tested in a FSA operant chamber and were trained to lever press for high-fat food pellets under a fixed-ratio (FR1) and a progressive ratio (PR) schedule. After sixteen days of PR sessions, rats were treated with three different doses of BC (1, 10 and 20 mg/kg). No significant differences were found between the two strains in the number of active lever presses. BC treatment (10 mg/kg and 20 mg/kg) increased the number of active lever presses (10 mg/kg having the strongest effect) whereas it decreased rat chow intake in the home cage with equivalent effects in both strains. These effects were not observed on the day of BC administration but on the day following its administration. Our results suggest that these two strains have similar motivation for procuring high fat food using this paradigm. BC increased operant responding for high-fat pellets but decreased chow intake in both strains, suggesting that D2R stimulation may have enhanced the motivational drive to procure the fatty food while correspondingly decreasing the intake of regular food. These findings suggest that susceptibility to dietary obesity (prior to the onset of obesity) may not affect operant motivation for a palatable high fat food and that differential susceptibility to obesity may be related to differential sensitivity to D2R stimulation.     

D-cycloserine facilitates extinction of cocaine self-administration in C57 mice

Introduction: Cocaine is a highly addictive drug of abuse for which there are currently no medications. In rats and mice d‐cycloserine (DCS), a partial NMDA agonist, accelerates extinction of cocaine seeking behavior. Since cues delay extinction here, we evaluated the effects d‐cycloserine in extinction with and without the presence of cues. Methods: Two doses of DCS (15 and 30 mg/kg) were studied in C57 mice. Mice self‐administered cocaine (1 mg/kg) for 2 weeks and then underwent a 20‐day extinction period where DCS was administered i.p. immediately following each daily session. Extinction was conducted in some mice with the presence of cocaine‐paired cues; while others were in the absence of these cues. Results: DCS treated mice (either dose) showed significantly reduced lever pressing during extinction with cue exposures when compared with vehicle treated mice. Without cues, animals showed much lower levels of lever pressing but the differences between vehicle and DCS were not significant. Conclusion: DCS accelerated extinction with the presence of cues, but there were no differences on extinction without cues as compared with vehicle. These findings are consistent with DCS disrupting the memory process associated with the cues. Since drug cues are significantly involved in relapse, these findings support research to assess the therapeutic potential of DCS in cocaine addiction. Synapse 2011. © 2011 Wiley‐Liss, Inc.     

D-cycloserine facilitates extinction of cocaine self-administration in rats

Previous research has indicated that D-cycloserine [DCS; a N-methyl-D-aspartate (NMDA) partial agonist] facilitates the extinction of conditioned fear as well as the extinction of cocaine conditioned place preference. Sprague Dawley rats were first trained to self-administer cocaine and then we compared their extinction behavior (lever pressing) following treatment with vehicle; 15 mg/kg DCS; or 30 mg/kg DCS. We showed that 30 mg/kg DCS, but not 15 mg/kg significantly accelerated extinction of cocaine self-administration behavior when compared with saline by almost half (4 days vs. 9 days). At 2 weeks when all animals had extinguished, there were no longer differences between the groups. The present findings support of the potential of NMDA partial agonists as prospectively valuable in facilitating the extinction of cocaine-seeking behavior. More specifically, we demonstrate that 30 mg/kg DCS was effective at significantly accelerating the extinction of cocaine self-administration behavior in rats. These results provide further support for the potential of DCS as a treatment strategy for addiction.     

Linking young and old institutionalized people.

A proprietary nursing home for the elderly in the State of North Carolina succeeded in pairing itself for joint activities of residents with an institution for the young mentally retarded. The young and old residents of the two homes were thus enabled to help each other, and thereby to help themselves as well. For the nursing home residents, this program provided an opportunity to engage in respected volunteer work and to regain a meaningful role in the community. It is believed that indications drawn from this demonstration of interaction between a nursing home and a home for the mentally retarded can aid in farther planning of such arrangements and in identifying research needs and potentials. Although only relatively few of the mildly impaired elderly in the nursing home volunteered for the joint activity, the ripple effect of the project extended beyond the direct participants. Since residents of the two institutions alternated visits, nonparticipants had a chance to observe and even participate in the activities for short periods. Even those who chose not to participate at all shared in the enriched conversation that resulted from this experience. The project was obviously a source of satisfaction and pride to residents of the nursing home, and the activity was eagerly received by the mentally retarded youngsters. The program demonstrates that aged persons in nursing homes can be tapped as a resource for providing service to institutionalized mentally retarded children and that a mutually beneficial relationship between the two institutions can accompany such service. Many leads for worthwhile research emerge from this pilot project.     

Evidence-Based Choice of Esophageal Stent for the Palliative Management of Malignant Dysphagia

BACKGROUND: The type of stent used for the management of patients with malignant dysphagia is chosen according to subjective physician's preference. There is no recent study available to provide updated evidence on early outcomes related to the use of different types of stents. METHODS: A literature search was performed using Embase, MEDLINE, Cochrane Library, and Google Scholar databases for comparative studies assessing different types of stents. The primary end point was stent-related mortality; secondary end points included: stent-related morbidity, successful palliation of dysphagia, and 30-day mortality. A random-effects model was used and heterogeneity was assessed. RESULTS: Twelve studies that included 911 patients compared metallic (46.54%) and plastic stents (53.45%), and eight studies that included 564 patients compared covered (43.26%) and uncovered metal stents (56.73%). Meta-analysis of randomized, controlled trials showed that metallic stents were associated with significantly reduced stent-related mortality (1.7% vs. 11.1% for the plastic group, odds ratio (OR), 0.2; 95% confidence interval (CI), 0.06-0.74; P = 0.02), morbidity in the form of reduced esophageal perforation (1.4% vs. 9.4% for plastic stent, OR, 0.27; 95% CI, 0.08-0.89; P = 0.03), and stent migration, yet increased rate of tumor in-growth (13% vs. 1.6% for plastic stents, OR, 4.84; 95% CI, 0.99-23.76; P = 0.05). Covered metallic stents had significantly less tumor in-growth than the uncovered and an increased migration rate. There was no significant difference between metallic and plastic stents in terms of any other stent-related morbidity and 30-day mortality. CONCLUSION: Self-expanding metallic stents are superior to plastic stents in terms of stent insertion-related mortality, morbidity, and quality of palliation. The uncovered variety is disadvantaged by high rate of tumor in-growth; adequately designed randomized, controlled trials need to examine outcomes and cost-effectiveness of covered versus uncovered metallic stents.     

Transplants of encapsulated rat choroid plexus cells exert neuroprotection in a rodent model of Huntington's disease

Choroid plexus (CP) epithelial cells secrete several neurotrophic factors and have been used in transplantation studies designed to impart neuroprotection against central nervous system (CNS) trauma. In the present study, CP was isolated from adult rats, encapsulated within alginate microcapsules, and transplanted unilaterally into the rat striatum. Three days later, unilateral injections of quinolinic acid (QA; 225 nmol) were made into the ipsilateral striatum to mimic the pathology observed in Huntington's disease (HD). After surgery, animals were tested for motor function using the placement test. Rats receiving CP transplants were significantly less impaired on this test. Nissl-stained sections demonstrated that CP transplants significantly reduced the volume of the striatal lesion produced by QA. Quantitative analysis of striatal neurons further demonstrated that choline acetyltransferase-immunoreactive, but not diaphorase-positive, neurons were protected by CP transplants. These data demonstrate that transplanted CP cells can be used to protect striatal neurons from excitotoxic damage and that the pattern of neuroprotection varies across specific neuronal populations.