Changes in the secretion and glycosylation of fibronectin by human skin fibroblasts associated with tuberous sclerosis

Fibroblasts from skin and skin lesions of patients with tuberous sclerosis (TS) and from skin of normal individuals were grown in culture. ELISA showed that the spent medium of those derived from TS skin lesions contained significantly more fibronectin (FN) than spent medium from the other cells. Amino acid compositional analysis of the FN from TS and normal sources revealed no substantial differences. However the FN of fibroblasts from TS-skin lesions was shown by HPAEC to contain a two- to three-fold increased content of carbohydrate. The changed monosaccharide composition was consistent with an increased content of N- and O-linked glycans and with the former containing polylactosamine chains. Fibroblasts from a normal individual were shown to proliferate more slowly and to produce larger cells when grown on FN from a TS skin lesion compared to growth on FN from normal skin. This revised version was published online in November 2006 with corrections to the Cover Date.     

Fragmented and scrambled mitochondrial ribosomal RNA coding regions among green algae: a model for their origin and evolution

Mitochondrial ribosomal RNA coding regions in the only three green algal taxa investigated to date are fundamentally different in that they are continuous in Prototheca wickerhamii, but highly fragmented and scrambled in Chlamydomonas reinhardtii and Chlamydomonas eugametos. To gain more insight into the mode of evolution of fragmented and scrambled mitochondrial ribosomal RNA (rRNA) genes within the green algal group, this work (1) provides additional information on fragmentation patterns of mitochondrial small- and large-subunit (SSU and LSU) rRNAs that strongly supports the concept of a gradual increase in the extent of discontinuity of mitochondrial rRNAs among chlorophycean green algae and (2) reports the first example of fragmented and scrambled mitochondrial LSU rRNA coding regions in a green algal taxon outside the Chlamydomonas group. The present study (1) suggests that the scrambling of the mitochondrial rRNA coding regions may have occurred early in the evolution of fragmented and scrambled mitochondrial rRNA genes within the chlorophycean green algal group, most likely in parallel with the fragmentation events, (2) proposes recombination as a possible mechanism involved in the evolution of these mitochondrial rRNA genes, and (3) presents a hypothetical pathway for converting continuous mitochondrial rRNA genes into the highly fragmented and scrambled rRNA coding regions of Chlamydomonas through a series of recombinatorial events between short repeated sequences.      

Identification of an axonal kinesin-3 motor for fast anterograde vesicle transport that facilitates retrograde transport of neuropeptides

A screen for genes required in Drosophila eye development identified an UNC-104/Kif1 related kinesin-3 microtubule motor. Analysis of mutants suggested that Drosophila Unc-104 has neuronal functions that are distinct from those of the classic anterograde axonal motor, kinesin-1. In particular, unc-104 mutations did not cause the distal paralysis and focal axonal swellings characteristic of kinesin-1 (Khc) mutations. However, like Khc mutations, unc-104 mutations caused motoneuron terminal atrophy. The distributions and transport behaviors of green fluorescent protein-tagged organelles in motor axons indicate that Unc-104 is a major contributor to the anterograde fast transport of neuropeptide-filled vesicles, that it also contributes to anterograde transport of synaptotagmin-bearing vesicles, and that it contributes little or nothing to anterograde transport of mitochondria, which are transported primarily by Khc. Remarkably, unc-104 mutations inhibited retrograde runs by neurosecretory vesicles but not by the other two organelles. This suggests that Unc-104, a member of an anterograde kinesin subfamily, contributes to an organelle-specific dynein-driven retrograde transport mechanism.     

Large-scale identification of polymorphic microsatellites using an <Emphasis Type="Italic">in silico</Emphasis> approach

Background  

Simple Sequence Repeat (SSR) or microsatellite markers are valuable for genetic research. Experimental methods to develop SSR markers are laborious, time consuming and expensive. In silico approaches have become a practicable and relatively inexpensive alternative during the last decade, although testing putative SSR markers still is time consuming and expensive. In many species only a relatively small percentage of SSR markers turn out to be polymorphic. This is particularly true for markers derived from expressed sequence tags (ESTs). In EST databases a large redundancy of sequences is present, which may contain information on length-polymorphisms in the SSR they contain, and whether they have been derived from heterozygotes or from different genotypes. Up to now, although a number of programs have been developed to identify SSRs in EST sequences, no software can detect putatively polymorphic SSRs.     

Mental practice-based rehabilitation training to improve arm function and daily activity performance in stroke patients: a randomized clinical trial

Background  

Over 50% of patients with upper limb paresis resulting from stroke face long-term impaired arm function and ensuing disability in daily life. Unfortunately, the number of effective treatments aimed at improving arm function due to stroke is still low. This study aims to evaluate a new therapy for improving arm function in sub-acute stroke patients based on mental practice theories and functional task-oriented training, and to study the predictors for a positive treatment result. It is hypothesized that a six-week, mental practice-based training program (additional to regular therapy) targeting the specific upper extremity skills important to the individual patient will significantly improve both arm function and daily activity performance, as well as being cost effective.