The novel and taxonomically restricted Ah24 gene from grain amaranth (Amaranthus hypochondriacus) has a dual role in development and defense

Grain amaranths tolerate stress and produce highly nutritious seeds. We have identified several (a)biotic stress-responsive genes of unknown function in Amaranthus hypochondriacus, including the so-called Ah24 gene. Ah24 was expressed in young or developing tissues; it was also strongly induced by mechanical damage, insect herbivory and methyl jasmonate and in meristems and newly emerging leaves of severely defoliated plants. Interestingly, an in silico analysis of its 1304 bp promoter region showed a predominance of regulatory boxes involved in development, but not in defense. The Ah24 cDNA encodes a predicted cytosolic protein of 164 amino acids, the localization of which was confirmed by confocal microscopy. Additional in silico analysis identified several other Ah24 homologs, present almost exclusively in plants belonging to the Caryophyllales. The possible function of this gene in planta was examined in transgenic Ah24 overexpressing Arabidopsis thaliana and Nicotiana tabacum plants. Transformed Arabidopsis showed enhanced vegetative growth and increased leaf number with no penalty in one fitness component, such as seed yield, in experimental conditions. Transgenic tobacco plants, which grew and reproduced normally, had increased insect herbivory resistance. Modified vegetative growth in transgenic Arabidopsis coincided with significant changes in the expression of genes controlling phytohormone synthesis or signaling, whereas increased resistance to insect herbivory in transgenic tobacco coincided with higher jasmonic acid and proteinase inhibitor activity levels, plus the accumulation of nicotine and several other putative defense-related metabolites. It is proposed that the primary role of the Ah24 gene in A. hypochondriacus is to contribute to a rapid recovery post-wounding or defoliation, although its participation in defense against insect herbivory is also plausible

Influence of DFNB1 status on expressive language in deaf children with cochlear implants

OBJECTIVE: The objective of this study was to compare the language growth of children with connexin-related deafness (DFNB1) who received cochlear implants versus the language growth of implanted children with non-DFNB1 deafness. STUDY DESIGN: A prospective longitudinal observational study and analysis. SETTING: Two tertiary referral centers. PATIENTS: There were 37 children with severe to profound hearing loss who received cochlear implants before the age of 5 years. INTERVENTIONS: A standardized language measure, the section for expressive language of the Reynell Developmental Language Scale (RDLS) was used to assess expressive language skills at two times post-implantation (14 months and 57 months post-implantation). Molecular screening for DFNB1 gene variants. MAIN OUTCOME MEASURES: Language quotient (LQ) scores (i.e. age equivalent score obtained on the RDLS divided by the child’s chronological age), results of genotyping. RESULTS: The mean language age at the second time interval (mean ± standard deviation [SD]: 51.8 ± 13 months) was greater than at the first testing session (mean ± SD: 19 ± 8 months, p<0.001, Wilcoxon signed rank test). When divided by genotype, DFNB1 children exhibited a higher LQ and less variability in scores than non-DFNB1 children at the second testing interval (Wilcoxon sign rank test, p=0.0034). A regression analysis (linear-fit by least squares) conducted on 26 children with pre-implantation audiometric data showed that DFNB1 status was the independent variable with greater predictive effect on LQ at the second testing interval, followed by age at implantation (R Square = 0.35, p=0.0479). CONCLUSION: Deaf children who received cochlear implants before the age of 5 years and use oral-communication show substantial improvement in language abilities. In this study, DFNB1 children who use cochlear implants show greater gains in expressive language than non-DFNB1 children, independent of residual hearing, age at implantation and duration of implant use

Performance after cochlear implantation in DFNB1 patients

To evaluate the speech perception and language development with cochlear implants (CI) of DFNB1 children in comparison with non-DFNB1 deaf children. Retrospective case series. Academic tertiary center. Thirty-one congenitally deafened children, screened for GJB2 allele variants, were followed for an average 32 months after CI. With the use of age-appropriate testing, 75% of DFNB1 and 53% of non-DFNB1 children achieved open set word recognition (speech perception category [SPC] level 6). Multivariate analysis showed that SPC was primarily dependent on duration of CI use, but not on the cause of hearing loss. In Reynell language tests, DFNB1 children showed more consistent and quicker gains than non-DFNB1 children. Although children with CI with DFNB1 show faster gains in Reynell scores, duration of CI use appears to have a greater effect on speech perception than DFNB1 status. Identification of DFNB1 children is useful in counseling of CI outcomes

Vitamin D status in relation to postural stability in the elderly

Objectives: Postural instability (PI) is an important risk factor for falls, especially in the frail older population. In this study, we investigated the impact of vitamin D deficiency on PI in a sample of community dwelling older subjects. Our objective was to determine the potential association between vitamin D deficiency and PI in older fallers. Design: Cross-sectional study. Setting: Falls and Fractures Clinic, Department of Geriatric Medicine, Nepean Hospital, Penrith, Australia. Participants: One hundred and forty-five adults aged 65 years and older who have had at least one episode of a fall within the six months prior to assessment at the Falls and Fractures Clinic. Measurements: Serum 25(OH) vitamin D3 [25(OH)D3] and parathyroid hormone concentrations were determined at baseline. Subjects were separated into 3 groups based on serum 25(OH)D3 levels with the following cut-off values: 50 nmol/L (normal). Other baseline measurements included body mass index, mini-nutritional assessment, grip strength, serum calcium concentration and creatinine clearance, which were used as covariables. PI was assessed using a computerized virtual reality system (Medicaa, Uruguay). Measured parameters included limits of stability (LOS) and centre of pressure (COP) under eyes closed on foam (ECF) and visio-vestibular stimulation. The estimated swaying area, computed from the ellipse of confidence under eyes closed standing on foam (ECF), was also used as a PI parameter. Gait velocity (GV) was measured using a GaitRITE walkway system. Results: Posture was impaired in vitamin D deficiency (<30 nmol/L) as indicated by lower LOS (90 +/- 18), higher ECF (25 +/- 10) and slower GV (55 +/- 7) as compared with the insufficient and normal groups. After adjustment for demographic, biochemical and anthropometric variables, vitamin D deficiency significantly correlated with low LOS and high COP under ECF. Conclusion: Low levels of vitamin D were associated with PI. This association could also have an effect on slow GV and increased risk of falls. In conclusion, using an objective method to measure balance in older fallers we have identified a novel role of vitamin D in balance control. Prospective studies are required to confirm the effect of vitamin D on PI and elucidate the mechanisms of this association

Effects of balance training using a virtual-reality system in older fallers

Poor balance is considered a challenging risk factor for falls in older adults. Therefore, innovative interventions for balance improvement in this population are greatly needed. The aim of this study was to evaluate the effect of a new virtual-reality system (the Balance Rehabilitation Unit [BRU]) on balance, falls, and fear of falling in a population of community-dwelling older subjects with a known history of falls. In this study, 60 community-dwelling older subjects were recruited after being diagnosed with poor balance at the Falls and Fractures Clinic, Nepean Hospital (Penrith, NSW, Australia). Subjects were randomly assigned to either the BRU-training or control groups. Both groups received the usual falls prevention care. The BRU-training group attended balance training (two sessions/week for 6 weeks) using an established protocol. Change in balance parameters was assessed in the BRU-training group at the end of their 6-week training program. Both groups were assessed 9 months after their initial assessment (month 0). Adherence to the BRU-training program was 97%. Balance parameters were significantly improved in the BRU-training group (P < 0.01). This effect was also associated with a significant reduction in falls and lower levels of fear of falling (P < 0.01). Some components of balance that were improved by BRU training showed a decline after 9 months post-training. In conclusion, BRU training is an effective and well-accepted intervention to improve balance, increase confidence, and prevent falls in the elderly