488 research outputs found

    Controlled release of human growth hormone fused with a human hybrid Fc fragment through a nanoporous polymer membrane

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    Nanotechnology has been applied to the development of more effective and compatible drug delivery systems for therapeutic proteins. Human growth hormone (hGH) was fused with a hybrid Fc fragment containing partial Fc domains of human IgD and IgG(4) to produce a long-acting fusion protein. The fusion protein, hGH-hyFc, resulted in the increase of the hydrodynamic diameter (ca. 11 nm) compared with the diameter (ca. 5 nm) of the recombinant hGH. A diblock copolymer membrane with nanopores (average diameter of 14.3 nm) exhibited a constant release rate of hGH-hyFc. The hGH-hyFc protein released in a controlled manner for one month was found to trigger the phosphorylation of Janus kinase 2 (JAK2) in human B lymphocyte and to exhibit an almost identical circular dichroism spectrum to that of the original hGH-hyFc, suggesting that the released fusion protein should maintain the functional and structural integrity of hGH. Thus, the nanoporous release device could be a potential delivery system for the long-term controlled release of therapeutic proteins fused with the hybrid Fc fragment.X111313sciescopu

    Expression, purification and crystallization of recombinant human TRAIL

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    Use of signal sequences as an in situ removable sequence element to stimulate protein synthesis in cell-free extracts

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    This study developed a method to boost the expression of recombinant proteins in a cell-free protein synthesis system without leaving additional amino acid residues. It was found that the nucleotide sequences of the signal peptides serve as an efficient downstream box to stimulate protein synthesis when they were fused upstream of the target genes. The extent of stimulation was critically affected by the identity of the second codons of the signal sequences. Moreover, the yield of the synthesized protein was enhanced by as much as 10 times in the presence of an optimal second codon. The signal peptides were in situ cleaved and the target proteins were produced in their native sizes by carrying out the cell-free synthesis reactions in the presence of Triton X-100, most likely through the activation of signal peptidase in the S30 extract. The amplification of the template DNA and the addition of the signal sequences were accomplished by PCR. Hence, elevated levels of recombinant proteins were generated within several hours

    Adenosine washing improves the retention rate of fat grafts under conditions of obesity

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    Background Fat grafting is a commonly employed aesthetic procedure for contour enhancement. However, outcome prediction is challenging due to the complex regeneration and remodeling processes involved. We investigated whether adenosine improves engraftment and fat graft survival under conditions of obesity. Methods Fat was harvested from mice fed a high-fat diet. This fat was washed with either Krebs-Ringer bicarbonate HEPES buffer (the vehicle group) or a buffer containing 500 nM adenosine (the adenosine wash group). Subsequently, the fat was transplanted into normal mice at 0.2 mL per mouse. In both groups, 50% of the mice were sacrificed at 1 week and the remainder at 4 weeks post-transplantation. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis was conducted during week 1. In week 4, micro-computed tomography, immunofluorescence staining, and RT-qPCR were performed. A sample of the initially harvested fat was set aside for lipolysis assay. Results Adenosine washing improved fat graft retention volumes by up to 50%. One week post-transplantation, the expression of adipogenic and angiogenic genes was found to be upregulated in the adenosine wash group. After 4 weeks, immunofluorescence staining revealed greater adipocyte integrity and an increased number of vessels. Furthermore, adenosine appeared to modulate inflammation by stabilizing the lipolysis rate. Conclusions Adenosine washing increased the fat graft survival rate under conditions of obesity. Clinically, this suggests a simple, cost-effective adjuvant method for improving fat graft survival in individuals with obesity. Further research is warranted to elucidate the underlying mechanisms and explore the applicability of this technique for autologous transplantation

    Anesthetic experience of an adult patient with an unrecognized tracheal bronchus -A case report-

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    We present a case of problematic tracheal intubation in an adult patient with an unrecognized tracheal bronchus. Immediately after tracheal intubation and position change to prone, bilateral breath sounds were almost absent, and there was a diminished tidal volume. In order to resolve the ventilatory difficulty, the wire-reinforced tube was replaced with a conventional tube, and proper positioning of the tube was completed under fiberoptic guidance. A tracheal bronchus (originating about 1.2 cm above the carina, and supplying the right upper lobe) was found on the postoperative chest CT. In the presence of tracheal bronchus, tracheal intubation may cause pulmonary complications. Anesthesiologists should keep in mind the anesthetic implications of tracheal bronchus, and must be familiar with the use of fiberoptic bronchoscopy for proper positioning of endotracheal tube

    Ionothermal Synthesis of a Novel 3D Cobalt Coordination Polymer with a Uniquely Reported Framework: [BMI] 2

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    The framework of [RMI]2[Co2(BTC)2(H2O)2] (RMI = 1-alkyl-3-methylimidazolium, alkyl; ethyl (EMI); propyl (PMI); butyl (BMI)), which has uniquely occurred in ionothermal reactions of metal salts and H3BTC (1,3,5-benzenetricarboxylic acid), an organic ligand, reappeared in this work. Ionothermal reaction of cobalt acetate and H3BTC with [BMI]Br ionic liquid as the reaction medium yielded the novel coordination polymer [BMI]2[Co2(BTC)2(H2O)2] (compound B2). Similar ionothermal reactions with different [EMI]Br and [PMI]Br as the reaction media have been previously reported to produce [EMI]2[Co3(BTC)2(OAc)2] (compound A1) and [PMI]2[Co2(BTC)2(H2O)2] (compound B1), respectively. In contrast with the trinuclear secondary building unit of A1, the framework structure of B1 and B2 consists of dinuclear secondary building units in common, but with subtle distinction posed by the different size of the incorporated cations. These structural differences amidst the frameworks showed interesting aspects, including guest and void volume, and were used to explain the chemical trend observed in the system. Moreover, the physicochemical properties of the newly synthesized compound have been briefly discussed
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