An analysis of paramagnetic centers in irradiated dentin using electron spin resonance

Summary The ESR spectra produced in irradiated dentin have been studied over a range of incident radiation energies from 50 kVp to 25 MVp. The behavior of the dentin ESR signal strength is similar to that of enamel as a function of the energy of the incident radiation. The magnitude of the dentin ESR signals are, however, up to 10 times smaller than the signals of dental enamel for a given radiation energy. The possible contributions of radiation interaction coefficients, chemical structure, and crystallite size to the differences in ESR spectra are discussed.     

BUILDING COMMUNITY: Developing Skills for Interprofessional Health Professions Education and Relationship-Centered Care

In 1995, the National League for Nursing commissioned a Panel on Interdisciplinary/Transdisciplinary Education. The focus of the Panel's work was to examine educational issues that transcend the health professions and to make recommendations for future implementation of an interdisciplinary approach to addressing them. This article is being simultaneously published by several professional journals. The goal is to seek as much feedback as possible.     

Minorities and AIDS

A common misconception is held among many ethnic minoritiesin San Francisco that AIDS is exclusively a ‘gay whitemale disease’. This myth is false, but dangerous. To assistethnic minorities in understanding their risks for AIDS, successfuleducational programs for these populations must recognize thediversity within these communities, including their differingcultures, languages and religious backgrounds. San Franciscohas adopted a model that utilizes well-established and well-respectedcommunity-based organizations to provide the education and riskreduction programs. Utilizing these organizations allows foreducation of diverse populations that is culturally and linguisticallyrelevant, thus allowing San Francisco an opportunity to preventthe national minority AIDS statistics from occurring withinits boundaries.     

Neurotensin injected into the nucleus accumbens blocks the psychostimulant effects of cocaine but does not attenuate cocaine self-administration in the rat

The neuropeptide neurotensin (NT) has been shown to modulate mesolimbic dopaminergic activity. Neurotensin injected into the VTA produces motor stimulation and release of dopamine in the nucleus accumbens. In contrast, when neurotensin is administered into the nucleus accumbens, it produces neuroleptic-like effects such as attenuation of the locomotor activity elicited by psychostimulants. In the present study, the hypothesis that neurotensin injected into the nucleus accumbens might modulate the psychostimulant and reinforcing actions of cocaine was tested. In experiment one, rats were trained to self-administer cocaine intravenously on an FR5 schedule of reinforcement. Following the establishment of baseline responding, rats were implanted with bilateral cannulae in the nucleus accumbens. One week later, rats were injected into the nucleus accumbens with various doses of neurotensin (4.2, 8.4 and 16.7 μg, total doses bilaterally) immediately prior to the self-administration session. No significant effects were found with any of the doses of neurotensin tested on the self-administration of cocaine. However, in experiment 2, neurotensin at doses of 4.2 and 16.7 μg injected into the nucleus accumbens significantly reduced the locomotor activation induced by an acute injection of cocaine (15 mg/kg i.p.) and a dose of 16.7 μg attenuated the locomotor activation induced by amphetamine (0.75 mg/kg i.p.). Thus, neurotensin in the nucleus accumbens appears to specifically modulate the acute locomotor activating properties of cocaine but not cocaine self-administration. Different mechanisms by which NT interacts with dopamine in the nucleus accumbens may provide a means of selectively altering psychostimulant motor actions without affecting psychostimulant reinforcement.     

Effects of accumbens DALA microinjections on brain stimulation reward and behavioral activation in intact and 6-OHDA treated rats

The effects of bilateral nucleus accumbens microinjections ofd-ala-met-enkephalinamide (DALA) were assessed in behavioral activation and lateral hypothalamic self-stimulation (LHSS) rate-frequency curve-shift paradigms in normal and accumbens 6-OHDA (4.0 µg) treated rats. Microinjections of DALA (2.5 µg/µl) in the behavioral activation paradigm had little effect on normal activity; however, DALA administered to 6-OHDA treated rats produced a significant overall increase in locomotion. The 6-OHDA DALA-induced locomotion effect peaked at 2 weeks after 6-OHDA treatment and then returned to baseline levels by week 5 posttreatment. Using LHSS, DALA tested over a range of doses (2.5, 5, 10, 20 µg/µl) displayed a weak biphasic reward effect only at the highest dose, which was characterized by an initial suppression followed by an elevation. DALA significantly depressed initial operant motor/performance in LHSS in a dose dependent fashion. Micro-injections of the normally ineffective low dose of DALA (2.5 µg/µl) following accumbens 6-OHDA treatment produced a significant LHSS reward decrease 2 weeks posttreatment, while LHSS motor/performance was relatively unaffected. Results are discussed in terms of opiate-dopamine and limbic-motor interactions.     

The role of general hospitals in the privatization of inpatient treatment for serious mental illness.

For almost three decades, many have regarded general hospital psychiatric units as the most appropriate setting for acute treatment of persons with serious mental illness who were once treated mostly in state hospitals. The extent to which this transfer has taken place and the differences between public and private general hospitals have been unclear. Using data from the 1988 National Mental Health Facilities Study and published data from the 1970s, the authors found that nearly half of all general hospitals providing psychiatric services treat persons with serious mental illness. Significant differences in case and payer mix were observed between public and private general hospitals, although these differences were smaller than in the 1970s. The findings suggest increased involvement by private general hospitals in treating patients reimbursed by public payers, but the findings also indicate that persons with serious mental illness and those using Medicaid are still more prevalent in public general hospitals than in private ones.     

PRETERM BIRTH PREVENTION PROGRAMS: A Critique of Current Literature

Published reports of the effectiveness of preterm birth prevention programs have produced mixed results. Many larger observational studies suggest benefit. The randomized trials, however, suggest no effect on reducing rates of preterm birth in high-risk populations. This article reviews and critiques these reports and suggests areas for further research.     

Effects of Positive and Negative Mood on Sexual Arousal in Sexually Functional Males

Effects of positive and negative musical mood induction on subjective and objective sexual arousal were examined in a group of sexually functional males (N = 24). Subjects evidenced significantly greater objective and subjective sexual response in the positive mood induction condition relative to both baseline and a neutral control condition. In contrast, the negative mood induction condition yielded significantly less objective sexual arousal than baseline and a neutral control condition. Data provide additional empirical support for the hypothesized impact of mood on sexual arousal.