380 research outputs found
Single-cell delineation of lineage and genetic identity in the mouse brain
During neurogenesis, mitotic progenitor cells lining the ventricles ofthe embryonic mouse brain undergo their final rounds of cell division, giving rise to a wide spectrum of postmitotic neurons and glia(1,2). The link between developmental lineage and cell-type diversity remains an open question. Here we used massively parallel tagging of progenitors to track clonal relationships and transcriptomic signatures during mouse forebrain development. We quantified clonal divergence and convergence across all major cell classes postnatally, and found diverse types of GABAergic neuron that share a common lineage. Divergence of GABAergic clones occurred during embryogenesis upon cell-cycle exit, suggesting that differentiation into subtypes is initiated as a lineage-dependent process at the progenitor cell level
Identification of the polypeptides of the major light-harvesting complex of photosystem II (LHCII) with their genes in tomato
Using an improved SDS-PAGE system, the polypeptides of the major chlorophyll a/b light-harvesting complex of PSII (LHCII) from tomato leaves were resolved into five polypeptide bands. All the polypeptides were matched with the genes encoding them by comparing amino acid sequences of tryptic peptides with gene sequences. The two major LHCII bands (usually comigrating as a `27 kDa' polypeptide) were encoded by cab1 and cab3 (Type I LHCII) genes. A third strong band or about 25 kDa was encoded by cab4 (Type II) genes. Polypeptides from two minor bands of 23-24 kDa were not N-teminally blocked; their N-terminal sequences showed they were Type III LHCII proteins. One complete cDNA clone and several incomplete clones for Type III polypeptides were sequenced. Combined with the peptide sequences, the results indicate that there are at least four different Type III genes in tomato, encoding four almost identical polypeptides. Thus, all the LHCII CAB polypeptides have been identified, and each type of LHCII polypeptide is encoded by distinct gene or genes in tomato.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29980/1/0000344.pd
Sonic Hedgehog Is a Chemoattractant for Midbrain Dopaminergic Axons
Midbrain dopaminergic axons project from the substantia nigra (SN) and the ventral tegmental area (VTA) to rostral target tissues, including the striatum, pallidum, and hypothalamus. The axons from the medially located VTA project primarily to more medial target tissues in the forebrain, whereas the more lateral SN axons project to lateral targets including the dorsolateral striatum. This structural diversity underlies the distinct functions of these pathways. Although a number of guidance cues have been implicated in the formation of the distinct axonal projections of the SN and VTA, the molecular basis of their diversity remains unclear. Here we investigate the molecular basis of structural diversity in mDN axonal projections. We find that Sonic Hedgehog (Shh) is expressed at a choice point in the course of the rostral dopaminergic projections. Furthermore, in midbrain explants, dopaminergic projections are attracted to a Shh source. Finally, in mice in which Shh signaling is inactivated during late neuronal development, the most medial dopaminergic projections are deficient
Auxetic foam for snowsport safety devices
Skiing and snowboarding are popular snow-sports with inherent risk of injury. There is potential to reduce the prevalence of injuries by improving and implementing snow-sport safety devices with the application of advanced materials. This paper investigates the application of auxetic foam to snow-sport safety devices. Composite pads - consisting of foam covered with a semi-rigid shell - were investigated as a simple model of body armour and a large 70 x 355 x 355 mm auxetic foam sample was fabricated as an example crash barrier. The thermo-mechanical conversion process was applied to convert open-cell polyurethane foam to auxetic foam. The composite pad with auxetic foam absorbed around three times more energy than the conventional equivalent under quasi-static compression with a concentrated load, indicating potential for body armour applications. An adapted thermo-mechanical process - utilising through-thickness rods to control in-plane compression - was applied to fabricate the large sample with relatively consistent properties throughout, indicating further potential for fabrication of a full size auxetic crash barrier. Further work will create full size prototypes of snow-sport safety devices with comparative testing against current products
Sequence of a tomato gene encoding a third type of LHCII chlorophyll a/b -binding polypeptide
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43429/1/11103_2004_Article_BF00037074.pd
Leflunomide in the treatment of patients with early rheumatoid arthritis—results of a prospective non-interventional study
Leflunomide is effective and well tolerated in the treatment of rheumatoid arthritis (RA), however, data on its use in early RA are scarce. This study seeks to evaluate effectiveness and safety of leflunomide in the treatment of early RA in daily practice. This prospective, open-label, non-interventional, multi-center study was carried out over 24 weeks including adults with early RA (≤1 year since diagnosis). Leflunomide treatment was according to label instructions. Three hundred thirty-four patients were included. Disease activity score in 28 joints (DAS28) response (reduction in DAS28 of >1.2 or reduction of >0.6 and a DAS28 of ≤5.1) was 71.9% at week 12 and 84.6% at week 24. 25.0% of patients achieved clinical remission (DAS28 ≤ 2.6). Most frequently reported adverse drug reactions (ADR) were diarrhea (3.0%), nausea (2.4%), hypertension (1.8%), and headache (1.5%). Serious ADR were reported in four patients (1.2%). Leflunomide showed the effectiveness which was to be expected from controlled studies without revealing any new or hitherto unknown side effects. Onset of action was quick and significant improvement of disease was seen after 12 weeks of therapy and at even higher rates after 24 weeks irrespective of the use of a loading dose. Interestingly, the DAS28-remission rate achieved was similar to the rate seen with methotrexate or biologic therapy in other studies
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