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PubMedDate not supplied

A single human gene encoding multiple tyrosine hydroxylases with different predicted functional characteristics.

Catecholaminergic systems in discrete regions of the brain are thought to be important in affective psychoses, learning and memory, reinforcement and sleep-wake cycle regulation. Tyrosine hydroxylase (TH) is the first enzyme in the pathway of catecholamine synthesis. Its importance is reflected in the diversity of the mechanisms that have been described which control its activity; TH levels vary both during development and as a function of the activity of the nervous system. Recently, we deduced the complete amino-acid sequence of rat TH from a complementary DNA clone encoding a functional enzyme. Here we demonstrate that, in man, TH molecules are encoded by at least three distinct messenger RNAs. The expression of these mRNAs varies in different parts of the nervous system. The sequence differences observed are confined to the 5' termini of the messengers and involve alternative splicing events. This variation has clear functional consequences for each putative form of the enzyme and could represent a novel means of regulating catecholamine levels in normal and pathological neurons.

Adrenal Gland Neoplasms↗
PubMed2004

The neurobiology of pair bonding.

A neurobiological model for pair-bond formation has emerged from studies in monogamous rodents. The neuropeptides oxytocin and vasopressin contribute to the processing of social cues necessary for individual recognition. Mesolimbic dopamine is involved in reinforcement and reward learning. Concurrent activation of neuropeptide and dopamine receptors in the reward centers of the brain during mating results in a conditioned partner preference, observed as a pair bond. Differential regulation of neuropeptide receptor expression may explain species differences in the ability to form pair bonds. These and other studies discussed here have intriguing implications for the neurobiology of social attachment in our own species.

Animals↗
PubMed2003

Simulated electrocortical activity at microscopic, mesoscopic, and global scales.

Simulation of electrocortical activity requires (a) determination of the most crucial features to be modelled, (b) specification of state equations with parameters that can be determined against independent measurements, and (c) explanation of electrical events in the brain at several scales. We report our attempts to address these problems, and show that mutually consistent explanations, and simulation of experimental data can be achieved for cortical gamma activity, synchronous oscillation, and the main features of the EEG power spectrum including the cerebral rhythms and evoked potentials. These simulations include consideration of dendritic and synaptic dynamics, AMPA, NMDA, and GABA receptors, and intracortical and cortical/subcortical interactions. We speculate on the way in which Hebbian learning and intrinsic reinforcement processes might complement the brain dynamics thus explained, to produce elementary cognitive operations.

Animals↗
PubMed1996

A qualitative analysis of student nurses' experiences of mentorship.

Increasing awareness of the incidence of stress amongst nurse learners, the introduction of continuous assessment of basic courses and successive and continuing ambiguous directives from the English National Board for Nursing, Midwifery and Health Visiting have led to widespread implementation of mentorship systems in this country. Considerable variation in terms of mentor selection, preparation, role and function clearly exists, against a background of questionable cultural relevance and suspect research. This small study, conducted as part of an honours' degree programme and completed in 1992, sought to find out what student nurses themselves thought about mentorship. Using group discussion and individual interviews, the views of 16 third-year students on a traditional RGN programme were explored, and the resulting qualitative data organized and presented using a method of thematic analysis. A ward culture is revealed, that not only continues to separate those with knowledge from those who need to learn, but also reinforces the position of the student through both covert and overt mechanisms of control. Examples of supportive, non-supportive and dissupportive relationships were described. Mentorship was described in terms of assessment and appraisal; the students apparent preoccupation with achieving a satisfactory ward report clearly influenced both their relationships and behaviour with trained staff. Mentorship for these students seemed to be more about control than support.

Attitude↗
PubMedDate not supplied

Using standardized patients in advanced practice nursing education.

Standardized patient encounters, a pedagogic approach to helping students develop appropriate clinical skills, are widely used in medical education and are being adopted by advanced practice nursing programs. Two types, simulated clinical encounters, in which students complete an episodic or comprehensive visit, and objective structured clinical experiences, multiple stations each presenting a different clinical problem, are used for formative and summative evaluation. Graduating adult and pediatric nurse practitioner students (N = 26) completed a simulated clinical encounter for an episodic visit. Students' performance on the simulated clinical encounter did not reflect their performance on other clinical evaluation measures or their performance on national certifying examinations. This one-time simulated clinical encounter was shown to lack the necessary reliability and validity to appropriately evaluate the clinical skills of nurse practitioner students. Videotaped, simulated patient encounters are useful, however as formative learning experiences. This reinforced our position that multiple site visits by faculty to students and their preceptors at all their clinical sites are necessary to accurately evaluate students' clinical performance.

Clinical Competence↗
PubMed2002

Care at the end of life: a novel curriculum module implemented by medical students.

End-of-life (EOL) and palliative care education in medical school curricula stand at a crossroads. Consensus has emerged that these topics merit systematic instruction throughout medical school training, yet curricula all too often consist of sporadic lectures focused on bioethics instead of clinical skills. The medical student authors identified a deficit in their curriculum, and designed and implemented an EOL curriculum module for their colleagues. In early 2000 the authors surveyed senior medical students about their experiences with EOL and palliative education, identifying deficits in clinical training and recommendations for interventions. They then designed a case-based educational module to teach EOL communication skills to medical students commencing clinical training. Faculty with national and local experience with EOL and palliative care reviewed the curriculum. Twelve of these faculty were oriented to the curriculum and then taught it in pairs to groups of 12 to 16 medical students in 2000 and 2001. The curriculum develops skills, attitudes, and knowledge relevant for communicating bad news and establishing treatment options in the EOL setting by utilizing trigger videos, group discussion, role plays, and case discussions. Approximately 75% of the 86 eligible students attended the module in 2000 and 2001. Feedback has guided the curriculum's refinement by the medical student authors. In addition, a standardized patient exercise, introduced in 2001, allowed students to reinforce the skills learned during the module.

Curriculum↗
PubMed2001

Applying social and behavioral theory as a template in containing and confining VRE.

Infection control professionals play several important roles--surveyors, educators, and ultimately change agents--in the identification and prevention of nosocomial infections in hospitals. The medical and surgical intensive care units (ICUs) in a large inner-city teaching hospital experienced an increased patient colonization rate with vancomycin-resistant enterococcus (VRE). Intervening in this problem required a multifaceted approach to control the spread of VRE and to change behavior by shifting social norms at multiple levels throughout the ICU community. The success of the interventions could be best explained by applying the use of several behavioral science models. The Ecological Model of Behavior Change, the Health Belief Model, and Social Cognitive Theory can be applied and are consistent with the successful interventions. This multifaceted approach to intervening in this problem consists of five levels of influence: (1) intrapersonal or individual factors, (2) interpersonal factors, (3) institutional factors, (4) community factors, and (5) public factors. We implemented educational inservices and developed references, policies, and programs directed at each of the five levels of influence. The Health Belief Model and Social Cognitive Theory were employed for intervention, and behavior change was based on modeling, observational learning, and vicarious reinforcement. Within six months of initial implementation, the number of positive VRE surveillance cultures and positive clinical isolates decreased significantly in both the medical and surgical ICUs. Two years later, there continues to be a marked reduction of VRE.

Behavior↗
PubMedDate not supplied

Strengthening the public health workforce: three CDC programs that prepare managers and leaders for the challenges of the 21st century.

To address the need for management development in public health, the Centers for Disease Control and Prevention (CDC) established three independent workforce development initiatives aimed primarily at strengthening management and leadership capacity: the Sustainable Management Development Program, the Management Academy for Public Health, and the CDC Leadership and Management Institute. Though independently designed and implemented, the programs share similar guiding principles in their approach to management development: interactive (adult) learning, management tools that reinforce evidence-based decision making, individual feedback, continuous improvement of the learning process, posttraining support for networking and life-long learning, and teamwork. This article will discuss important lessons learned regarding best practices in management and leadership development.

Centers for Disease Control and Prevention, U.S.↗
PubMed2005

Mice lacking the alpha4 nicotinic receptor subunit fail to modulate dopaminergic neuronal arbors and possess impaired dopamine transporter function.

Neuronal nicotinic acetylcholine receptors (nAChRs) at presynaptic sites can modulate dopaminergic synaptic transmission by regulating dopamine (DA) release and uptake. Dopaminergic transmission in nigrostriatal and mesolimbic pathways is vital for the coordination of movement and is associated with learning and behavioral reinforcement. We reported recently that the D2 DA receptor plays a central role in regulating the arbor size of substantia nigra dopaminergic neurons. Given the known effects of nAChRs on dopaminergic neurotransmission, we assessed the ability of the alpha4 nAChR subunit to regulate arbor size of dopaminergic neurons by comparing responses of wild-type and alpha4 nAChR subunit knockout [alpha4(-/-)] mice to long-term exposure to cocaine, amphetamine, nicotine, and haloperidol, and after substantia nigra neurotoxic lesioning. We found that dopaminergic neurons in adult drug-naive alpha4(-/-) mice had significantly larger terminal arbors, and despite normal short-term behavioral responses to drugs acting on pre- and postsynaptic D2 DA receptors, they were unable to modulate their terminal arbor in response to pharmacological manipulation or after lesioning. In addition, although synaptosome DA uptake studies showed that the interaction of the D2 DA receptor and the dopamine transporter (DAT) was preserved in alpha4(-/-) mice, DAT function was found to be impaired. These findings suggest that the alpha4 subunit of the nAChR is an independent regulator of terminal arbor size of nigrostriatal dopaminergic neurons and that reduced functionality of presynaptic DAT may contribute to this effect by impairing DA uptake.

Animals↗
PubMedDate not supplied

The AcCell series 2000 as a support system for training and evaluation in educational and clinical settings.

Providing effective training, retraining and evaluation programs, including proficiency testing programs, for cytoprofessionals is a challenge shared by many academic and clinical educators internationally. In cytopathology the quality of training has immediately transferable and critically important impacts on satisfactory performance in the clinical setting. Well-designed interactive computer-assisted instruction and testing programs have been shown to enhance initial learning and to reinforce factual and conceptual knowledge. Computer systems designed not only to promote diagnostic accuracy but to integrate and streamline work flow in clinical service settings are candidates for educational adaptation. The AcCell 2000 system, designed as a diagnostic screening support system, offers technology that is adaptable to educational needs during basic and in-service training as well as testing of screening proficiency in both locator and identification skills. We describe the considerations, approaches and applications of the AcCell 2000 system in education programs for both training and evaluation of gynecologic diagnostic screening proficiency.

Automation↗
PubMed1986

AIDS health education for intravenous drug users.

Intravenous (IV) drug users are the second largest risk group for AIDS and the main source of infection for heterosexual partner and pediatric AIDS cases. IV drug users have an addiction and a subculture that make risk reduction difficult; for example, to refuse to share needles can endanger personal relationships, and carrying clean works (rather than renting them in a shooting gallery) risks arrest. In New York City, at least, knowledge about AIDS transmission is widespread among IV drug users, and most drug injectors report having changed their drug use practices to reduce their risks. The main functions of health education in areas where IV drug users have this level of knowledge are to disseminate news of new discoveries; reach those drug users who have not yet learned AIDS basics; reinforce what is already known; and provide information about new programs to help drug users deal with AIDS-related problems. To encourage behavior change requires going beyond simple education, however; it entails trying to change IV drug user subculture. Drug user groups in the Netherlands and in New York City are attempting to do this from within the subculture. Outside intervention requires repeated messages from multiple sources; face-to-face, interactive communication; and perhaps the use of ex-addicts as health educators.

Acquired Immunodeficiency Syndrome↗
PubMed2005

Effects of lesions of the nucleus accumbens core on choice between small certain rewards and large uncertain rewards in rats.

BACKGROUND: Animals must frequently make choices between alternative courses of action, seeking to maximize the benefit obtained. They must therefore evaluate the magnitude and the likelihood of the available outcomes. Little is known of the neural basis of this process, or what might predispose individuals to be overly conservative or to take risks excessively (avoiding or preferring uncertainty, respectively). The nucleus accumbens core (AcbC) is known to contribute to rats' ability to choose large, delayed rewards over small, immediate rewards; AcbC lesions cause impulsive choice and an impairment in learning with delayed reinforcement. However, it is not known how the AcbC contributes to choice involving probabilistic reinforcement, such as between a large, uncertain reward and a small, certain reward. We examined the effects of excitotoxic lesions of the AcbC on probabilistic choice in rats. RESULTS: Rats chose between a single food pellet delivered with certainty (p = 1) and four food pellets delivered with varying degrees of uncertainty (p = 1, 0.5, 0.25, 0.125, and 0.0625) in a discrete-trial task, with the large-reinforcer probability decreasing or increasing across the session. Subjects were trained on this task and then received excitotoxic or sham lesions of the AcbC before being retested. After a transient period during which AcbC-lesioned rats exhibited relative indifference between the two alternatives compared to controls, AcbC-lesioned rats came to exhibit risk-averse choice, choosing the large reinforcer less often than controls when it was uncertain, to the extent that they obtained less food as a result. Rats behaved as if indifferent between a single certain pellet and four pellets at p = 0.32 (sham-operated) or at p = 0.70 (AcbC-lesioned) by the end of testing. When the probabilities did not vary across the session, AcbC-lesioned rats and controls strongly preferred the large reinforcer when it was certain, and strongly preferred the small reinforcer when the large reinforcer was very unlikely (p = 0.0625), with no differences between AcbC-lesioned and sham-operated groups. CONCLUSION: These results support the view that the AcbC contributes to action selection by promoting the choice of uncertain, as well as delayed, reinforcement.

Animals↗