Does vision therapy for visual information processing improve academic performance? A randomised clinical trial.

PURPOSE: To determine whether a typical vision therapy (VT) programme designed to improve visual information processing (VIP) skills is effective in improving these skills and/or academic performance. METHODS: We used a double-blind, randomised clinical trial to compare VIP VT to placebo training. Participating schools referred a sample of 579 early primary school children identified as being within the lower third of their class for literacy. From the referred sample, we identified 247 children eligible to participate (passed visions and auditory processing screening, and VIP performance <34th percentile), 94 of whom participated. Matching IQ, school grade and sex was achieved by sorting hierarchically on these values and then alternately allocating to VT or placebo groups. Both programmes ran for 10 weeks and consisted of 33 h working at home and 4 h working in office. The VT programme was indicative of that employed in Australian paediatric optometry practices, with the placebo programme containing similar activities, except targeting skills within a child's competencies and with specific VIP development activities removed. The main outcome measures were score change on three standardised educational tests (reading comprehension, spelling and mathematics) and six VIP tests, both immediately post-intervention (PI) and 6 months later. RESULTS: Sixty-nine children completed the programmes. The VT programme produced no significant improvement in the three educational tests or in five of the six VIP tests compared to the control. The VT programme improved visual sequential memory (VSM) by a moderate amount compared to the control (Cohen's d = 0.57 and 0.52, immediately PI and at 6 months, respectively: p < 0.03 and p < 0.02). CONCLUSIONS: The VIP and academic performance benefits from a VT programme were largely identical to those from a control programme, both immediately and 6-month PI. Placebo effects and general effects such as improvements in executive function and/or regression-to-the-mean could be mistaken for specific programme effectiveness.

An isotope dilution-precipitation process for removing radioactive cesium from wastewater.

A novel isotope dilution-precipitation method has been developed to remove cesium-137 from radioactive wastewater. The process involves adding stable cesium chloride to wastewater in order to raise the total cesium concentration, which then allows both the stable and radioactive cesium ions to be precipitated together using sodium tetraphenylborate. This process was investigated utilizing laboratory solutions to determine stable cesium dose rates, mixing times, effects of pH, and filtration requirements. Once optimized, the process was then tested on synthetic wastewater and aqueous low-level waste. Experiments showed the reaction to be very quick and stable in the pH range tested, 2.5-11.5. The wastewater may need to be filtered using a 0.45-µm filter, though ferric sulfate has been shown to promote coagulation and settling, thereby eliminating the necessity for filtration. This investigation showed that this isotope dilution-precipitation process can remove Cs-37 levels below the U.S. Department of Energy's (DOE) Derived Concentration Standard (DCS) of 3.0 × 10(-6) µCi/mL using a single dosage, potentially allowing the wastewater to be discharged directly to sanitary sewers.

Radiological dispersal device outdoor simulation test: cesium chloride particle characteristics.

Particles were generated from the detonation of simulated radiological dispersal devices (RDDs) using non-radioactive CsCl powder and explosive C4. The physical and chemical properties of the resulting particles were characterized. Two RDD simulation tests were conducted at Lawrence Livermore National Laboratory: one of the simulated RDDs was positioned 1m above a steel plate and the other was partially buried in soil. Particles were collected with filters at a distance of 150 m from the origin of the RDD device, and particle mass concentrations were monitored to identify the particle plume intensity using real time particle samplers. Particles collected on filters were analyzed via computer-controlled scanning electron microscopy coupled with energy dispersive X-ray spectrometry (CCSEM/EDX) to determine their size distribution, morphology, and chemical constituents. This analysis showed that particles generated by the detonation of explosives can be associated with other materials (e.g., soil) that are in close proximity to the RDD device and that the morphology and chemical makeup of the particles change depending on the interactions of the RDD device with the surrounding materials.

Comparing attentional skills in children with acquired and developmental central nervous system disorders.

Attentional impairments in children occur in the context of both developmental and acquired disorders involving the central nervous system (CNS) and may have implications for ongoing development, potentially impeding cognitive, educational, and behavioral functions. Using a continuous performance paradigm (CPT), this study compared attentional profiles of children with developmental and acquired conditions impacting on the CNS: (i) attention deficit-hyperactivity disorder (ADHD: n=27); (ii) moderate traumatic brain injury (TBI: n=41); (iii) acute lymphoblastic leukemia (n=31); and (iv) insulin-dependent diabetes mellitus (n=39). A healthy control group (n=46) was also examined. Groups were compared on measures of sustained attention, selective attention, and response inhibition. In addition, measures of performance variability and deterioration and processing speed were examined. Results showed that children with ADHD exhibited global and severe attentional impairments in contrast to all other groups. Children with moderate TBI displayed mild attentional difficulties, restricted to selective and sustained attention domains. In conclusion, although CPT parameters differentiated the ADHD group from all others, a disorder-specific profile was not observed.

FMRI lateralization of expressive language in children with cerebral lesions.

PURPOSE: Lateralization of language function is crucial to the planning of surgery in children with frontal or temporal lobe lesions. We examined the utility of functional magnetic resonance imaging (fMRI) as a determinant of lateralization of expressive language in children with cerebral lesions. METHODS: fMRI language lateralization was attempted in 35 children (29 with epilepsy) aged 8-18 years with frontal or temporal lobe lesions (28 left hemisphere, five right hemisphere, two bilateral). Axial and coronal fMRI scans through the frontal and temporal lobes were acquired at 1.5 Tesla by using a block-design, covert word-generation paradigm. Activation maps were lateralized by blinded visual inspection and quantitative asymmetry indices (hemispheric and inferior frontal regions of interest, at p<0.001 uncorrected and p<0.05 Bonferroni corrected). RESULTS: Thirty children showed significant activation in the inferior frontal gyrus. Lateralization by visual inspection was left in 21, right in six, and bilateral in three, and concordant with hemispheric and inferior frontal quantitative lateralization in 93% of cases. Developmental tumors and dysplasias involving the inferior left frontal lobe had activation overlying or abutting the lesion in five of six cases. fMRI language lateralization was corroborated in six children by frontal cortex stimulation or intracarotid amytal testing and indirectly supported by aphasiology in a further six cases. In two children, fMRI language lateralization was bilateral, and corroborative methods of language lateralization were left. Neither lesion lateralization, patient handedness, nor developmental versus acquired nature of the lesion was associated with language lateralization. Involvement of the left inferior or middle frontal gyri increased the likelihood of atypical language lateralization. CONCLUSIONS: fMRI lateralizes language in children with cerebral lesions, although caution is needed in interpretation of individual results.

Identification of a novel protein with a role in lipoarabinomannan biosynthesis in mycobacteria.

All species of Mycobacteria synthesize distinctive cell walls that are rich in phosphatidylinositol mannosides (PIMs), lipomannan (LM), and lipoarabinomannan (LAM). PIM glycolipids, having 2-4 mannose residues, can either be channeled into polar PIM species (with 6 Man residues) or hypermannosylated to form LM and LAM. In this study, we have identified a Mycobacterium smegmatis gene, termed lpqW, that is required for the conversion of PIMs to LAM and is highly conserved in all mycobacteria. A transposon mutant, Myco481, containing an insertion near the 3' end of lpqW exhibited altered colony morphology on complex agar medium. This mutant was unstable and was consistently overgrown by a second mutant, represented by Myco481.1, that had normal growth and colony characteristics. Biochemical analysis and metabolic labeling studies showed that Myco481 synthesized the complete spectrum of apolar and polar PIMs but was unable to make LAM. LAM biosynthesis was restored to near wild type levels in Myco481.1. However, this mutant was unable to synthesize the major polar PIM (AcPIM6) and accumulated a smaller intermediate, AcPIM4. Targeted disruption of the lpqW gene and complementation of the initial Myco481 mutant with the wild type gene confirmed that the phenotype of this mutant was due to loss of LpqW. These studies suggest that LpqW has a role in regulating the flux of early PIM intermediates into polar PIM or LAM biosynthesis. They also suggest that AcPIM4 is the likely branch point intermediate in polar PIM and LAM biosynthesis.

A controlled, prospective study of neuropsychological outcomes post parathyroidectomy in primary hyperparathyroid patients.

BACKGROUND: There is an increasing number of primary hyperparathyroidism (PHPT) patients with neuropsychological or psychiatric symptoms. Many of these patients do not have osseous or renal complications to satisfy the criteria for parathyroidectomy according to the NIH guidelines. OBJECTIVE: To assess whether there is any improvement in neuropsychological and mood symptoms following parathyroidectomy. PATIENTS AND DESIGN: Twenty PHPT patients undergoing parathyroidectomy and 20 orthopaedic controls matched for age, gender and estimated intelligence were subjects to pre and postoperative assessment of cognition and mood with a mean surgery-retest interval of 3 months. RESULTS: Using two tests of attentional flexibility [the Stroop test, the Digit symbol test of the Wechsler Adult Intelligence Scale-Revised (WAIS-R)], and two memory tests for prose and nonverbal material, no significant change was found between the groups when comparing scores before and after surgery. There was no improvement between pre and postoperative measures of verbal (dominant hemisphere) as opposed to visuo-spatial (nondominant hemisphere) function when compared to controls. There was no relationship between the reduction in serum calcium and the change in the neuropsychological measures postoperatively. CONCLUSION: This controlled, prospective study demonstrates no significant improvement in neuropsychological indices using objective, validated psychometric tools in an unselected cohort of PHPT patients. No relationship was found between serum calcium level and the degree of neuropsychological deficit. More studies are needed to assess whether the effect of parathyroidectomy is beneficial and sustainable in PHPT patients with neuropsychological symptoms alone.

Measures of maternal-fetal interaction in day-30 bovine pregnancies derived from nuclear transfer.

Embryonic mortality and abnormal placental morphology have been reported by most researchers studying nuclear transfer (NT), and it now is accepted that placental anomalies and poor development of cloned embryos are related. As early as day 50 of gestation, cloned bovine concepti exhibit poor structural organization of the developing placentomes. These experiments were designed to identify alterations in maternal-fetal interactions during establishment of the placentas of NT-derived embryos at day 30 of gestation. Bovine NT embryos were produced using cultured fibroblast cells from a single Hereford donor cow, and control embryos were derived from in vitro fertilization (IVF). Following in vivo culture in ligated sheep oviducts, day-8 blastocysts were transferred to synchronized recipient heifers. Tissues recovered from viable day-30 pregnancies were analyzed by real-time RT-PCR, immunohistochemistry, and quantitative histological techniques. Immunoperoxidase staining of caruncular tissue from NT- and IVF-derived pregnancies revealed no significant differences in expression of the extracellular matrix proteins, collagen type IV and laminin, or the receptor subunits, integrins alpha1 and alpha3, suggesting that altered expression of these proteins at day 30 of gestation is not a primary cause of abnormal placentome structure in cloned concepti. Percentage of binucleate cells (BNC) within the trophoblast also was similar in NT- and IVF-derived pregnancies; however, expression of the BNC-specific placental lactogen (PL) transcript was elevated in NT-derived concepti (p < 0.05). These results indicate that regulation of PL transcription was altered in cloned day-30 placental tissues, suggesting the presence of irregular fetal-maternal signaling patterns that might undermine continued development of NT-derived concepti.

Attempts to enhance production of porcine chimeras from embryonic germ cells and preimplantation embryos.

Porcine embryonic germ (EG) cells share common features with porcine embryonic stem (ES) cells, including morphology, alkaline phosphatase activity and capacity for in vitro differentiation. Porcine EG cells are also capable of in vivo development by producing chimeras after blastocyst injection; however, the proportion of injected embryos that yield a chimera and the proportion of cells contributed by the cultured cells in each chimera are too low for practical use in genetic manipulation. Moreover, somatic, but not germ-line chimerism, has been reported from blastocyst injection using porcine ES or EG cells. To test whether efficiency of chimera production from blastocyst injection can be improved upon by changing the host embryo, we used as host embryos four groups according to developmental stage or length in culture: fresh 4-cell and 8-cell stage embryos subsequently cultured into blastocysts, fresh morulae, fresh blastocysts, and cultured blastocysts. Injection and embryo transfer of fresh and cultured blastocysts produced similar percentages of live piglets (17% versus 19%). Four piglets were judged to have a small degree of pigmentation chimerism, but microsatellite analysis failed to confirm chimerism in these or other piglets. Polymerase chain reaction analysis for detection of the porcine SRY gene in female piglets born from embryos injected with male EG cells identified six chimeras, at least one, but not more than two, from each treatment. Chimerism was confirmed in two putative pigmentation chimeras and in four piglets without overt signs of chimerism. The low percentage of injected embryos that yielded a chimera and the small contribution by EG cells to development of each confirmed chimera indicated that procedural changes in how EG cells were combined with host embryos were unsuccessful in increasing the likelihood that porcine EG cells will participate in embryonic development. Alternatively, our results suggested that improvements are needed in EG cell isolation and culture procedures to ensure in vitro maintenance of EG cell developmental capacity.

Collaboration among nurse executives in complex environments: fostering administrative best practice.

In the past decade, many healthcare institutions have formed new partnerships, alliances, and networks. Collaboration among chief nursing officers and other leaders from affiliating institutions is essential to the success of these new organizational structures. The authors explore the nature of the collaboration among chief nursing officers and senior nurse leaders at 5 Harvard-affiliated teaching hospitals that provide cancer care. In particular, this article examines how collaborative relationships have been fostered and highlights the challenges, benefits, and outcomes of successful cross-institutional collaboration.

Methodologic issues in a population-based health survey of Gulf War veterans.

This report describes the principal methods used in the development, conduct, and analysis of the research study "Health Assessment of Persian Gulf War Veterans from Iowa" (Iowa Gulf War Study). The methods presented include an outline of the organizational structure, study timeline, hypotheses, outcome definitions, and study design. Adhering to a strict timeline, the study protocol and instruments were developed, and a stratified sample of 3,695 military personnel (76% participation) was located and surveyed by structured telephone interview. The study tracked personnel from all service branches residing nationally and internationally, including those discharged from service. This study required development and implementation of methods appropriate to analysis of data collected in a complex sampling framework and methodological procedures to ensure scientific rigor in a highly public and politicized environment. Statistical analyses were conducted on a priori health outcomes and required development of methods to compute Cochran-Mantel-Haenszel adjusted rate differences. This environment facilitated rapid implementation, critique by scientific and public advisors, a high participation rate, and rapid publication.

Differential functional magnetic resonance imaging language activation in twins discordant for a left frontal tumor.

Eight-year-old twins, one with a left frontal tumor and aphasic seizures, the other neurologically normal, underwent serial assessment of expressive language with functional magnetic resonance imaging and neuropsychology. The affected twin showed a significant amount of right hemisphere activation coincident with behavioral deterioration in expressive language and late growth in the tumor. This pattern of language dysfunction and the left language dominance of her co-twin suggested that the affected twin was also left dominant for language, and the significance of her right activation is discussed. We postulate that the right hemisphere activation represents a stabilizing mechanism in the context of a developmental and progressive lesion in language cortex rather than language transfer per se.