Principle-based ethics and nurses' attitudes towards artificial feeding

Nurses often institute artificial feeding for patients who would otherwise starve Recently, the courts in the United States have favoured withholding or withdrawing feedings from patients who currently refuse or previously gave some indication they would refuse artificial nutrition and hydration This paper investigates under what circumstances nurses feel justified in withholding artificial nutrition and hydration Structured interviews were conducted with 40 cancer care nurses from two sites, and 40 dementia care nurses from two sites The interviews were based on two vignettes, one involving an alert patient with terminal cancer, the other a patient suffering end-stage Alzheimer's dementia, and were analysed for themes coinciding with principles of deontological ethics Investigators found that autonomy, beneficence and non-maleficence most often guided nurses' decisions to withhold or implement artificial feeding     

Self-Concept and Satisfaction With Physical Appearance in Youth With and Without Oral Clefts

This study investigated relationships between child/parent dissatisfaction with child facial appearance and the self-concept/social competence of 8- to 15-year-old children with (N = 34) and without (N = 34) oral clefts. Children in both groups had normative psychosocial adjustment, but also reported moderate dissatisfaction with facial appearance. Cleft group parents were more likely to agree with their child's dissatisfaction. When cleft group parents were more dissatisfied with child facial appearance, their children reported better quality of life. Results suggest that parents of children with clefts reporting greater dissatisfaction may respond in positive ways that enhance quality of life.     

Resorption rate and biocompatibility characteristics of two polyester ventilation tubes in a guinea pig model

OBJECTIVES: Determine the resorption rate and biocompatibility characteristics of 2 polyester ventilation tubes, and to determine whether soap and water exposure accelerates polyester tube degradation. STUDY DESIGN AND SETTING: 50/50 poly (D, L-lactide-co-glycolide; PLGA-50) and poly (L-lactide; PLA) polymers were placed into the tympanic membranes of Hartley pigmented guinea pigs. Integrity of the tubes was determined by weekly otoscopic examination. Biocompatibility was assessed by comparing auditory brainstem response (ABR) thresholds and by examining tympanic membrane changes following tube resorption. Shah minigrommet ventilation tubes were used as controls. In the second portion of this study, implanted PLGA-50 and PLA tubes were exposed weekly to a mixture of soap and water (1:5) until complete resorption was observed. Biocompatibility was assessed by periodic ABR testing and tympanic membrane examination. RESULTS: The PLA tubes remained in the tympanic membrane for a longer period (63.2 +/- 19.3 days) than the PLGA-50 (18.8 +/- 8.1 days). The tympanic membrane and resorbable tube interface demonstrated equivalent findings for auditory thresholds and tissue histopathology at the implant site compared to nonresorbable controls. The resorption behavior was not altered by exposure to soap and water. Tympanic membranes of all animals following tube degradation and soap water exposure were intact with minimal scarring and no signs of persistent foreign body response. The histological analysis showed that implantation of resorbable tubes was not accompanied by secondary infection with otorrhea through the tube, did not result in a permanent perforation or dislocation of the tube into the middle ear cavity, and was not followed by excess tympanosclerosis or localized or diffuse membrane atrophy. CONCLUSIONS AND SIGNIFICANCE: Resorbable polyester pressure equalization tubes demonstrate predictable resorption behavior and similar biocompatibility characteristics when compared with nonresorbable Shah minigrommet ventilation tubes. Exposure to soap water does not accelerate polyester tube degradation nor change the host tissue response during the indwelling period or after complete resorption. The data suggests that resorbable ventilation tubes are substantially equivalent to other FDA-approved tympanostomy devices with regard to safety and biocompatibility in the guinea pig model examined and may provide improved clinical performance by combining this approach with sustained release technology. EBM RATING: B-2.     

MDMA produces stimulant-like conditioned locomotor activity

Daily administration of a drug in a distinctive environment establishes contingencies that support Pavlovian conditioning. Environmental cues that are paired with the drug injection and that predict the onset of drug action can become conditioned stimuli. Ultimately, the conditioned stimuli come to predict the availability of drug and develop the potential to engender conditioned drug responses. Various psychostimulant drugs can produce conditioned locotnotion when tested in the presence of environmental cues that were repeatedly associated with the drug experience. The ability of amphetamine and cocaine to produce conditioned locomotion was demonstrated in the present study. Stimulant-like properties of methylenedioxymethamphetamine (MDMA) have been reported in locomotor paradigms, drug discrimination procedures, and human subjective questionnaires. MDMA (5 mg/kg), paired for 5 days to a distinct environment signalled by the presence of a distinct odor, produced enhanced locomotion during a test probe with the odor alone indicating that MDMA can also produce conditioned locomotion. The observation that the stimulus properties of MDMA can also become associated with environmental cues supports the hypothesis that some of the behavioral effects of MDMA resemble those of other classical psychostimulants such as amphetamine and cocaine.This is publication number 5732BCR from the Research Institute of Scripps Clinic     

The effects of X monosomy on brain development: Monozygotic twins discorcant for Turner's syndrome

Monosomy for the X chromosome is the most frequent cause of Turner's syndrome, a common clinical syndrome associated with particular physical and neurobehavioral features. The results from comprehensive assessment of prepubertal monozygotic female twins discordant for X monosomy are presented. Zygosity was established with DNA Fingerprinting and no evidence of chromosomal mosaicism was seen in either child. Physical features in the affected twin were relatively mild with respect to the full spectrum of physical malformations and disabilities associated with Turner's syndrome. The neurobehavioral phenotypes of the twins were compared. Although both sisters scored in the superior range of intelligence, the affected twin's Performance IQ was 18 points less than her sister, whereas Verbal IQ showed only a 3-point difference between the sisters. Other relative differences were noted within the executive, visuospatial, and visuomotor domains of function. Behavioral evaluation indicated greater problems with attention, hyperactivity, and anxiety in the affected twin. Quantitative analysis of brain anatomy revealed evidence of both general and regional effects of X monosomy on neurodevelopment. Cerebrospinal fluid volume was increased by 25% in the affected twin compared with her sister with a corresponding decrease in gray matter volume. The right frontal, right parietal–occipital, and left parietal-perisylvian regions showed the greatest discrepancy between the sisters with respect to increased cerebrospinal fluid and decreased gray matter volumes in the twin with X monosomy. Differences in the posterior fossa were also noted with a 50% relative increase in the volumes of the fourth ventricle and cisterna magna and a 10 to 15% relative reduction in size of the cerebellar vermis, pons, and medulla in the affected twin. The association between the neurobehavioral and neuroanatomical findings in the affected twin is discussed. The unique nature of the naturally occurring genetic phenomenon seen in this twin pair provides an opportunity to more fully elucidate the neurobehavioral phenotype associated with X monosomy and Turner's syndrome.     

Synaptic modifications accompanying epileptogenesis in vitro: long-term depression of GABA-mediated inhibition

We used an in vitro model similar to kindling to examine the processes underlying epileptogenesis. A 60 Hz train was applied every 5–10 min to the Schaffer collateral pathways in guinea pig hippocampal slices until epileptiform bursting was elicited in the CA3 region. The resultant alterations in both spontaneous and evoked activities were studied using intracellular recordings from CA3 pyramidal cells. An attempt was made to elucidate the synaptic modifications responsible for the conversion to this state of enhanced excitability. Analyses revealed that the emergence of epileptiform discharge was accompanied by a long-term depression of evoked inhibitory conductances. This tetanus-induced reduction of inhibition involved both the early and late phases of the evoked hyperpolarization, suggesting modification of both the GABA_A and GABA_B receptor-mediated events. Previous studies have suggested that NMDA receptor activation plays an important role in the induction of epileptiform activity in this model. Our data, showing that depression of inhibition can be induced in the presence of CNQX, is consistent with this hypothesis. The parallel development of long-term depression of inhibition and epileptiform bursting following tetanic stimulation suggests that plasticity of the inhibitory transmission process is a potential source of vulnerability contributing to epileptogenesis.     

dazed gene is necessary for late cell type development and retinal cell maintenance in the zebrafish retina.

Several molecules, such as growth factors and neurotrophic factors, are required both for the differentiation of specific retinal cell types and the long-term cell survival of all retinal neurons. As diffusible factors, these molecules act non-cell-autonomously. Here, we describe the loss of function phenotype for dazed (dzd), a gene that acts cell-autonomously for retinal cell survival and affects the differentiation of rod photoreceptors and the Muller glia. By 3 days after fertilization, dazed mutant embryos have small eyes and slight heart edema. Acridine orange staining indicated a significant degree of retinal cell death occurring by 48 hr after fertilization, and histological analysis revealed that dying cells were found in the inner and outer nuclear layers and near the marginal zones. Although molecular and morphological differentiation of the inner retina and cone photoreceptors occurred, rod photoreceptors failed to differentiate beyond a small patch in the ventral retina and rod precursors failed to respond to exogenously added retinoic acid, which normally potentiated rod differentiation. Mosaic analysis indicated that the dazed gene acts cell-autonomously for rod production and cell survival, as dazed clones failed to produce rods outside the ventral patch and dazed cells were not maintained in wild-type hosts. Raising mutants under constant light resulted in severe retinal degeneration, whereas raising embryos under constant darkness did not provide any additional protection from cell death. Behavioral analysis showed that a subpopulation of adult fish that were heterozygous for the dazed mutation had elevated visual thresholds and were night blind, suggesting that dazed may also be required for long-term dim-light vision. Taken together, our studies suggest a role for the dazed gene in rod and Muller cell development and overall retinal cell survival and maintenance.     

Patient and partner perceptions about preventing genital herpes transmission

Research over the past decade has provided a new understanding of genital herpes transmission and measures that can reduce transmission risk. It is unclear, however, how those affected by genital herpes access and interpret this information to make decisions about risk behaviours. This study measured how people with genital herpes and their partners perceived prevention methods, barriers and facilitating factors, and information sources. Formative evaluation was conducted, and survey data were collected from visitors to four websites (n=1849). Results suggest that the prevention messages of refraining from sex during disease outbreaks and condom use have had the greatest reach. Misconceptions about the potential role of suppressive antiviral therapy for genital herpes prevention persist among a substantial percentage of respondents. Accurate information concerning transmission between outbreaks, the effectiveness of condoms and the role of antiviral medication is critical in preventing the spread of genital herpes.