85 research outputs found

    A new solvent system for paper chromatography separation of glucoronic and galacturonic acids

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32169/1/0000224.pd

    Bioabsorbable versus titanium screws in anterior cruciate ligament reconstruction using hamstring autograft: a prospective, blinded, randomized controlled trial with 5-year follow-up

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    Background: Longer term studies of bioabsorbable screws for ACL reconstruction are reported, but results are specific to the exact screw material and design. Titanium and PLLA-HA screw outcomes have been compared only to 2 years. Purpose: The aim of this study was to compare the clinical and radiological outcomes of PLLAHA screw (BS) versus a titanium screw (TS), for hamstring tendon anterior cruciate ligament reconstruction over 5 years. We hypothesized that there are no differences in clinical scores, and tunnel widening, between the BS and the TS groups, and that the PLLA-HA screw as seen on MRI should show high grade resorption and ossification response over 5 years. Methods: 40 patients undergoing ACLR were randomized to receive either a PLLA-HA screw (BS group) or a Titanium screw (TS group) for ACL fixation. Blinded evaluation was performed at 2 & 5 years with IKDC & Lysholm knee score, KT-1000 arthrometer, single legged hop test, and MRI to evaluate tunnel and screw volumes, peri-screw ossification, graft integration and cyst formation. Results: There was no difference in any clinical outcome measure at 2 or 5 years between the 2 groups. At 2 years, the BS femoral tunnel was smaller than the TS tunnel (p=0.02) and at 5 years, there was no difference. At 2 years the femoral BS screw was a mean 76% of its original volume and by 5 years, 36%. At 2 years the tibial BS screw mean volume was 68% of its original volume and by 5 years, 46%. At 5 years BS group 88% of femoral tunnels and 56% of tibial tunnels demonstrated a significant ossification response. There was no increase in cyst formation in the BS group and no screw breakages. Conclusion: Our study has shown equivalent clinical results between BS and TS groups at 2 and 5 years. This PLLA-HA screw was not associated with increased tunnel widening or cyst formation when compared with the titanium screw. The PLLA-HA screw demonstrated progressive screw resorption and gradual, but incomplete ossification over 5 years

    Hapten-radioimmunoassay: A general procedure for the estimation of steroidal and other haptenic substances

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    Hapten-radioimmunoassay may be used for sensitive and specific quantitation of low molecular weight substances which can be made immunogenic by conjugation to a protein, This method, which involves radioiodination of the protein-portion of the conjugate, has been used for quantitation of non-conjugated estrogenic steroids.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32963/1/0000346.pd

    Moments of inertia, nucleon axial-vector coupling, the {\bf 8}, {\bf 10}, 10ˉ\bar{\bf 10} and 273/2{\bf 27}_{3/2} mass spectrums and the higher SU(3)_f representation mass splittings in the Skyrme model

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    The broad importance of a recent experimental discovery of pentaquarks requires more theoretical insight into the structure of higher representation multiplets. The nucleon axial-vector coupling, moments of inertia, the {\bf 8}, {\bf 10}, 10ˉ\bar{\bf 10}, and 273/2{\bf 27}_{3/2} absolute mass spectra and the higher SU(3)f_f representation mass splittings for the multiplets 8{\bf 8}, 10{\bf 10}, 10ˉ\bar{\bf 10}, 27{\bf 27}, 35{\bf 35}, 35ˉ\bar{\bf 35}, and 64\bf 64 are computed in the framework of the minimal SU(3)f{\rm SU(3)_f} extended Skyrme model by using only one free parameter, i.e., the Skyrme charge ee. The analysis presented in this paper represents simple and clear theoretical estimates, obtained without using any experimental results for higher (10ˉ\bar{\bf 10},...) multiplets. The obtained results are in good agreement with other chiral soliton model approaches that more extensively use experimental results as inputs.Comment: 22 pages, 12 figures, 9 tables, version accepted in JHE

    Heterochromatin Protein 1β (HP1β) has distinct functions and distinct nuclear distribution in pluripotent versus differentiated cells

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    Background: Pluripotent embryonic stem cells (ESCs) have the unique ability to differentiate into every cell type and to self-renew. These characteristics correlate with a distinct nuclear architecture, epigenetic signatures enriched for active chromatin marks and hyperdynamic binding of structural chromatin proteins. Recently, several chromatin-related proteins have been shown to regulate ESC pluripotency and/or differentiation, yet the role of the major heterochromatin proteins in pluripotency is unknown. Results: Here we identify Heterochromatin Protein 1β (HP1β) as an essential protein for proper differentiation, and, unexpectedly, for the maintenance of pluripotency in ESCs. In pluripotent and differentiated cells HP1β is differentially localized and differentially associated with chromatin. Deletion of HP1β, but not HP1aα, in ESCs provokes a loss of the morphological and proliferative characteristics of embryonic pluripotent cells, reduces expression of pluripotency factors and causes aberrant differentiation. However, in differentiated cells, loss of HP1β has the opposite effect, perturbing maintenance of the differentiation state and facilitating reprogramming to an induced pluripotent state. Microscopy, biochemical fractionation and chromatin immunoprecipitation reveal a diffuse nucleoplasmic distribution, weak association with chromatin and high expression levels for HP1β in ESCs. The minor fraction of HP1β that is chromatin-bound in ESCs is enriched within exons, unlike the situation in differentiated cells, where it binds heterochromatic satellite repeats and chromocenters. Conclusions: We demonstrate an unexpected duality in the role of HP1β: it is essential in ESCs for maintaining pluripotency, while it is required for proper differentiation in differentiated cells. Thus, HP1β function both depends on, and regulates, the pluripotent state

    Preparation of protein-protein conjugates and some novel polyamino acid derivatives employing a bifunctional reagent

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32191/1/0000249.pd
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