No abstract

Significant benefits to musculoskeletal comfort, posture, and visual comfort were documented when participants used the adjustable task lights. Participants' assessments of the light's usability, usefulness and desirability were positive. There were no negative results found with adjustable task light use.

Low-density lipoproteins activate isolated human platelets. The mechanism of this activation is unknown, but may involve increased phosphoinositide turnover. We have examined the effect of low-density lipoproteins on intracellular calcium concentrations in platelets loaded with the photoprotein aequorin. The lipoproteins induced concentration-dependent increases in intracellular calcium, associated with shape change and aggregation.These responses could be partially inhibited by the removal of extracellular calcium and by pre-incubation with acetylsalicylic acid. They were also antagonised by agents which increase cellular concentrations of cyclic adenosine and guanosine monophosphates. It is not clear whether the platelet-lipoprotein interaction involves a 'classical' lipoprotein receptor.

Anophthalmia, microphthalmia, and coloboma are a genetically heterogeneous spectrum of developmental eye disorders and affect around 30 per 100,000 live births. OLFM2 encodes a secreted glycoprotein belonging to the noelin family of olfactomedin domain-containing proteins that modulate the timing of neuronal differentiation during development. OLFM2 SNPs have been associated with open angle glaucoma in a case-control study, and knockdown of Olfm2 in zebrafish results in reduced eye size. From a cohort of 258 individuals with developmental eye anomalies, we identified two with heterozygous variants in OLFM2: an individual with bilateral microphthalmia carrying a de novo 19p13.2 microdeletion involving OLFM2 and a second individual with unilateral microphthalmia and contralateral coloboma who had a novel single base change in the 5' untranslated region. Dual luciferase assays demonstrated that the latter variant causes a significant decrease in expression of OLFM2. Furthermore, RNA in situ hybridisation experiments using human developmental tissue revealed expression in relevant structures, including the lens vesicle and optic cup. Our study indicates that OLFM2 is likely to be important in mammalian eye development and disease and should be considered as a gene for human ocular anomalies.

Studies of a wide variety of organisms have shown that homologous sequences can exert a significant impact on each other, resulting in changes in gene sequence, gene expression, chromatin structure, and global chromosome architecture. Our work has focused on transvection, a process that can cause genes to be sensitive to the proximity of a homologue. Transvection is seen at the yellow gene of Drosophila, where it mediates numerous cases of intragenic complementation. In this article, we describe two approaches that have characterized the process of transvection at yellow. The first entailed a screen for mutations that support intragenic complementation at yellow. The second involved the analysis of 53 yellow alleles, obtained from a variety of sources, with respect to complementation, molecular structure, and transcriptional competence. Our data suggest two ways in which transvection may be regulated at yellow: (1) a transcriptional mechanism, whereby the ability of an allele to support transvection is influenced by its transcriptional competency, and (2) a structural mechanism, whereby the pairing of structurally dissimilar homologues results in conformational changes that affect gene expression.