Transition in young adults with spina bifida: a qualitative study.

BACKGROUND: Adolescents and young adults with spina bifida are an at-risk population because of the complexity of their condition, developmental stage and social challenges. The purpose of this qualitative study was to examine the transition to adulthood in young adults with spina bifida and to explore condition-related needs and life skills required during the transition process. METHODS: This qualitative study using narrative inquiry was part of a larger multi-site study of adaptation in young adults with spina bifida. Interviews were completed with 10 participants ranging in age from 18 to 25 years. The guided interview questions focused on specific dimensions of the transition experience related to the ecological model: self-management, independence and inner strength. RESULTS: Three themes capturing different dimensions of the young adults' transition experiences emerged in the analysis. The themes included: (1) Struggling for independence, (2) Limiting social interactions and experiences with stigma, and (3) Building inner strength. CONCLUSION: The qualitative study contributes to a better understanding of the challenges of transition to achieve self-management and social development for young adults with spina bifida. Findings in the life stories highlighted issues that necessitate increased advocacy and interventions from professionals within the health and social system.

Motor proteins in cell division.

The movements of eukaryotic cell division depend upon the conversion of chemical energy into mechanical work, which in turn involves the actions of motor proteins, molecular transducers that generate force and motion relative cytoskeletal elements. In animal cells, microtubule-based motor proteins of the mitotic apparatus are involved in segregating chromosomes and perhaps in organizing the mitotic apparatus itself, while microfilament-based motors in the contractile ring generate the forces that separate daughter cells during cytokinesis. This review outlines recent advances in our understanding of the roles of molecular motors in mitosis and cytokinesis.

Regulation of cell polarity by microtubules in fission yeast.

To investigate the role of microtubules in regulating cell polarity in Schizosaccharomyces pombe, we have developed a system in which normally cylindrical fission yeast synchronously form branched cells at high frequency upon treatment with the microtubule-depolymerizing drug thiabendazole (TBZ). Branching depends on both elevated temperature and cell cycle state and occurs at high frequency only when TBZ is added to cells that have not yet passed through New-End Take-Off (NETO), the normal transition from monopolar to bipolar growth. This suggests that microtubules may be of greatest physiological importance for the maintenance of cell shape at specific points in the cell cycle. The localization of three different proteins normally found at cell ends-cortical F-actin, tea1, and an ral3 (scd2)-green fluorescent protein (GFP) fusion-is disrupted by TBZ treatment. However, these proteins can eventually return to cell ends in the absence of microtubules, indicating that although their localization to ends normally depends on microtubules, they may recover by alternative mechanisms. In addition, TBZ induces a shift in ral3-GFP distribution from cell ends to the cell middle, suggesting that a protein complex containing ral3 may be part of the cue that specifies the position of branch formation.

Mitotic spindle assembly by two different pathways in vitro.

We have used Xenopus egg extracts to study spindle morphogenesis in a cell-free system and have identified two pathways of spindle assembly in vitro using methods of fluorescent analogue cytochemistry. When demembranated sperm nuclei are added to egg extracts arrested in a mitotic state, individual nuclei direct the assembly of polarized microtubule arrays, which we term half-spindles; half-spindles then fuse pairwise to form bipolar spindles. In contrast, when sperm nuclei are added to extracts that are induced to enter interphase and arrested in the following mitosis, a single sperm nucleus can direct the assembly of a complete spindle. We find that microtubule arrays in vitro are strongly biased towards chromatin, but this does not depend on specific kinetochore-microtubule interactions. Indeed, although we have identified morphological and probably functional kinetochores in spindles assembled in vitro, kinetochores appear not to play an obligate role in the establishment of stable, bipolar microtubule arrays in either assembly pathway. Features of the two pathways suggest that spindle assembly involves a hierarchy of selective microtubule stabilization, involving both chromatin-microtubule interactions and antiparallel microtubule-microtubule interactions, and that fundamental molecular interactions are probably the same in both pathways. This in vitro reconstitution system should be useful for identifying the molecules regulating the generation of asymmetric microtubule arrays and for understanding spindle morphogenesis in general.

Poleward microtubule flux mitotic spindles assembled in vitro.

In the preceding paper we described pathways of mitotic spindle assembly in cell-free extracts prepared from eggs of Xenopus laevis. Here we demonstrate the poleward flux of microtubules in spindles assembled in vitro, using a photoactivatable fluorescein covalently coupled to tubulin and multi-channel fluorescence videomicroscopy. After local photoactivation of fluorescence by UV microbeam, we observed poleward movement of fluorescein-marked microtubules at a rate of 3 microns/min, similar to rates of chromosome movement and spindle elongation during prometaphase and anaphase. This movement could be blocked by the addition of millimolar AMP-PNP but was not affected by concentrations of vanadate up to 150 microM, suggesting that poleward flux may be driven by a microtubule motor similar to kinesin. In contrast to previous results obtained in vivo (Mitchison, T. J. 1989. J. Cell Biol. 109:637-652), poleward flux in vitro appears to occur independently of kinetochores or kinetochore microtubules, and therefore may be a general property of relatively stable microtubules within the spindle. We find that microtubules moving towards poles are dynamic structures, and we have estimated the average half-life of fluxing microtubules in vitro to be between approximately 75 and 100 s. We discuss these results with regard to the function of poleward flux in spindle movements in anaphase and prometaphase.

Microtubule dynamics: the view from the tip.

Recent studies have suggested that proteins found at the tips of microtubules in vertebrate cells may play an important role in intracellular membrane transport processes. Evidence from fission yeast indicates that such proteins can also regulate microtubule dynamics.

A switch in microtubule dynamics at the onset of anaphase B in the mitotic spindle of Schizosaccharomyces pombe.

Microtubule dynamics have key roles in mitotic spindle assembly and chromosome movement [1]. Fast turnover of spindle microtubules at metaphase and polewards flux of microtubules (polewards movement of the microtubule lattice with depolymerization at the poles) at both metaphase and anaphase have been observed in mammalian cells [2]. Imaging spindle dynamics in genetically tractable yeasts is now possible using green fluorescent protein (GFP)-tagging of tubulin and sites on chromosomes [3] [4] [5] [6] [7] [8]. We used photobleaching of GFP-labeled tubulin to observe microtubule dynamics in the fission yeast Schizosaccharomyces pombe. Photobleaching did not perturb progress through mitosis. Bleached marks made on the spindle during metaphase recovered their fluorescence rapidly, indicating fast microtubule turnover. Recovery was spatially non-uniform, but we found no evidence for polewards flux. Marks made during anaphase B did not recover fluorescence, and were observed to slide away from each other at the same rate as spindle elongation. Fast microtubule turnover at metaphase and a switch to stable microtubules at anaphase suggest the existence of a cell-cycle-regulated molecular switch that controls microtubule dynamics and that may be conserved in evolution. Unlike the situation for vertebrate spindles, microtubule depolymerization at poles and polewards flux may not occur in S. pombe mitosis. We conclude that GFP-tubulin photobleaching in conjunction with mutant cells should aid research on molecular mechanisms causing and regulating dynamics.

Mis-specification of cortical identity in a fission yeast PAK mutant.

The regulation of cell polarity in the fission yeast Schizosaccharomyces pombe is apparent in the restriction of extensile growth to the two ends of a cylindrically shaped cell, and in a specific transition - termed 'new-end take-off' (NETO) - between monopolar and bipolar growth mid-way through the cell cycle [1]. Several genes have been identified that affect one or more aspects of cell polarity (reviewed in [2] [3]), and the molecular pathways regulating cell polarity in fission yeast appear to be conserved among eukaryotes [3] [4] [5] [6] [7] [8] [9], but it is less clear how the proteins involved organize polarity at the level of the entire cell. Here, we describe novel cytological markers of cell polarity in fission yeast and their unusual localization in the monopolar growth mutant orb2-34, which carries a non-lethal mutation in the essential gene shk1(+)/pak1(+)/orb2(+), which encodes a p21-activated kinase (PAK) family member [8] [9] [10] [11] [12]. Our results suggest that, in contrast to other monopolar-growing mutants, the monopolar phenotype of the orb2-34 mutant might not be due to a defect in activating end growth per se, but rather reflects a failure of one of the cell ends to maintain the molecular properties that identify an end. Thus, one role of the Shk1/Pak1 kinase in vivo might be to contribute to how a cell recognizes its ends as sites for growth.

Microtubule flux in mitosis is independent of chromosomes, centrosomes, and antiparallel microtubules.

We investigated the mechanism of poleward microtubule flux in the mitotic spindle by generating spindle subassemblies in Xenopus egg extracts in vitro and assaying their ability to flux by photoactivation of fluorescence and low-light multichannel fluorescence video-microscopy. We find that monopolar intermediates of in vitro spindle assembly (half-spindles) exhibit normal poleward flux, as do astral microtubule arrays induced by the addition of dimethyl sulfoxide to egg extracts in the absence of both chromosomes and conventional centrosomes. Immunodepletion of the kinesin-related microtubule motor protein Eg5, a candidate flux motor, suggests that Eg5 is not required for flux. These results suggest that poleward flux is a basic element of microtubule behavior exhibited by even simple self-organized microtubule arrays and presumably underlies the most elementary levels of spindle morphogenesis.

Whole genomewide linkage screen for neural tube defects reveals regions of interest on chromosomes 7 and 10.

Neural tube defects (NTDs) are the second most common birth defects (1 in 1000 live births) in the world. Periconceptional maternal folate supplementation reduces NTD risk by 50-70%; however, studies of folate related and other developmental genes in humans have failed to definitively identify a major causal gene for NTD. The aetiology of NTDs remains unknown and both genetic and environmental factors are implicated. We present findings from a microsatellite based screen of 44 multiplex pedigrees ascertained through the NTD Collaborative Group. For the linkage analysis, we defined our phenotype narrowly by considering individuals with a lumbosacral level myelomeningocele as affected, then we expanded the phenotype to include all types of NTDs. Two point parametric analyses were performed using VITESSE and HOMOG. Multipoint parametric and nonparametric analyses were performed using ALLEGRO. Initial results identified chromosomes 7 and 10, both with maximum parametric multipoint lod scores (Mlod) >2.0. Chromosome 7 produced the highest score in the 24 cM interval between D7S3056 and D7S3051 (parametric Mlod 2.45; nonparametric Mlod 1.89). Further investigation demonstrated that results on chromosome 7 were being primarily driven by a single large pedigree (parametric Mlod 2.40). When this family was removed from analysis, chromosome 10 was the most interesting region, with a peak Mlod of 2.25 at D10S1731. Based on mouse human synteny, two candidate genes (Meox2, Twist1) were identified on chromosome 7. A review of public databases revealed three biologically plausible candidates (FGFR2, GFRA1, Pax2) on chromosome 10. The results from this screen provide valuable positional data for prioritisation of candidate gene assessment in future studies of NTDs.

Microtubules and Ca2+-sequestering membranes in the mitotic apparatus, isolated by a new method.

The mitotic apparatus of sea urchin embryos was isolated using a polyethylene glycol (PEG)/EGTA-medium. Such a procedure preserves the birefringence and the Ca2+ lability of the isolated mitotic apparatus. The method of isolation gives good preservation of the microtubules and of the intracellular Ca2+-transport system as visualized by a monoclonal antibody to a 46-kDa protein. Triple fluorescence studies allow a comparison of the relative locations of microtubules, Ca2+-sequestering membranes and chromatin (by Hoechst 33342) in the mitotic apparatus. We find that the Ca2+-sequestering membranes are concentrated mainly in the centers of the asters and do not follow the distribution of microtubules in the mitotic apparatus. Regulation of microtubules by Ca2+ may not depend on immediate contiguity of microtubules and the Ca2+-regulating sites.

Camp experiences and attitudes toward epilepsy: a pilot study.

Most healthcare providers report anecdotally that a camping experience helps children and adolescents with chronic health conditions to develop more positive attitudes toward their condition. However, children's and adolescents' perceptions have rarely been studied systematically. This pilot study of 20 campers with epilepsy who were 8-16 years of age was undertaken to examine the effect of a camp experience on their attitudes toward epilepsy. Attitudes, measured by the 13-item Child Attitude Toward Illness Scale (CATIS), were assessed before and after the camp experience. No pretest or posttest difference in attitude toward epilepsy was found in the total group. However, when attitudes were examined by seizure frequency, there was a trend for those with more frequent seizures to report a more positive attitude after the camp experience. Issues in evaluating camp experiences for youth with chronic conditions are reviewed, and recommendations are made for a comprehensive camp evaluation. Nurses are encouraged to assist families whose child is challenged by more frequent seizures to consider a camp experience.

Teaching strategies used by expert nurse practitioner preceptors: a qualitative study.

Nurse practitioner (NP) programs utilize expert clinicians as preceptors for their students. Little is written regarding this important role. This study explored teaching strategies used by expert preceptors. Fifteen preceptors in a master's level NP program participated in this qualitative study. The study identified (a) orientation strategies, (b) strategies used with all students, and (c) strategies used differentially according to level of learner. Two distinct preceptor styles emerged from the data ("incremental structure" and "sink or swim"). Preceptors also identified characteristics of student readiness for increased responsibility. Results of this qualitative study can be helpful in preceptor orientation and continued education.

AIDS beliefs in young women: are they related to AIDS risk-reduction behavior?

Little is known about the relationship between AIDS beliefs and AIDS risk-reduction behavior, especially in young heterosexual adults. This study explores young women's beliefs and behavior regarding AIDS. The results of this exploratory study indicate that college women generally see AIDS as serious, do not see themselves as susceptible, and are uncertain if AIDS beliefs influence their contraceptive behavior. Higher susceptibility scores are consistently correlated with AIDS risk-reduction behavior, and women who believe that AIDS affects their contraceptive use are more likely to use condoms. Implications for practice and strategies to increase susceptibility in women at risk are discussed.

The AHCPR effectiveness initiatives: opportunities for rehabilitation nursing.

The creation of AHCPR and its effectiveness initiative is one factor moving nursing into a new decade of data-based decision making. The resources available from this agency can facilitate one of nursing's major goals: the delivery of quality care. It also can be an avenue for the Association of Rehabilitation Nurses and the Rehabilitation Nursing Foundation to play a major role in defining the research priorities for our field of practice.

Nursing diagnoses used most frequently in rehabilitation nursing practice.

This article describes a study of 346 rehabilitation nurses in which the nurses identified the nursing diagnoses most frequently used in rehabilitation. The study identified patterns of diagnosis used by nurses in inpatient and community settings, found no pattern of use by educational background, and delineated etiologies used with diagnoses characteristic of rehabilitation nursing.