1,149 research outputs found

    Insulin Solution Stability and Biocompatibility with Materials Used for an Implantable Insulin Delivery Device Using Reverse Phase HPLC Methods

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    open access articleAbstract: Insulin (Humulin® R IU500) has been delivered from an implantable artificial pancreas in diabetic rats and pigs. The artificial pancreas which was implanted in the peritoneum was fabricated from several biocompatible materials such as polycarbonate, stainless steel, polyurethane, titanium and a polyurethane resin. The device also contains a glucose responsive smart gel which controls the di usion of insulin dependent on the surrounding glucose environment. As the insulin reservoir is refillable and in contact with the device materials, assessing its biocompatibility with these various device component materials was conducted. Insulin can undergo chemical degradation mainly via a deamidation reaction on glutamine and asparagine residues rendering its biological hormone functionality. Two Reverse Phase High Performance Liquid Chromatography (RP-HPLC) methods were developed and validated for detection of insulin and degradant Asn A21 desamido insulin (method A) and insulin and degradant Asn B3 desamido insulin (method B). Material biocompatibility studies show that stainless steel and titanium are suitable for an implantable insulin delivery device design over a 31-day period. The use of polycarbonate and polyurethane could be considered if the insulin reservoir in the device was only to remain in the device for less than 11 days after which time there is a loss in cresol which acts in a protective capacity for insulin stability

    Informing a risk prediction model for binary outcomes with external coefficient information

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146799/1/rssc12306-sup-0001-SupInfo.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146799/2/rssc12306_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146799/3/rssc12306.pd

    Overexpression of Full-Length ETV1 Transcripts in Clinical Prostate Cancer Due to Gene Translocation

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    ETV1 is overexpressed in a subset of clinical prostate cancers as a fusion transcript with many different partners. However, ETV1 can also be overexpressed as a full-length transcript. Full-length ETV1 protein functions differently from truncated ETV1 produced by fusion genes. In this study we describe the genetic background of full-length ETV1 overexpression and the biological properties of different full-length ETV1 isoforms in prostate cancer. Break-apart FISH showed in five out of six patient samples with overexpression of full-length ETV1 a genomic rearrangement of the gene, indicating frequent translocation. We were able to study the rearrangements in more detail in two tumors. In the first tumor 5′-RACE on cDNA showed linkage of the complete ETV1 transcript to the first exon of a prostate-specific two exon ncRNA gene that maps on chromosome 14 (EST14). This resulted in the expression of both full-length ETV1 transcripts and EST14-ETV1 fusion transcripts. In chromosome spreads of a xenograft derived from the second prostate cancer we observed a complex ETV1 translocation involving a chromosome 7 fragment that harbors ETV1 and fragments of chromosomes 4 and 10. Further studies revealed the overexpression of several different full-length transcripts, giving rise to four protein isoforms with different N-terminal regions. Even the shortest isoform synthesized by full-length ETV1 stimulated in vitro anchorage-independent growth of PNT2C2 prostate cells. This contrasts the lack of activity of even shorter N-truncated ETV1 produced by fusion transcripts. Our findings that in clinical prostate cancer overexpression of full-length ETV1 is due to genomic rearrangements involving different chromosomes and the identification of a shortened biologically active ETV1 isoform are highly relevant for understanding the mechanism of ETV1 function in prostate cancer

    Urban Space, Politics, and Socio-ethnic Relations in Roma

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    Roma, written and directed by Alfonso Cuaron, has been one of the most successful Latin American films of recent decades, while also widely recognised as an important piece of social commentary, and a window on Mexico City in the early 1970s. The cinematography and storyline of the film offer insights into social change in the city, as well as the use of private and public space, and what this says about social and ethnic relations, as well as how business is carried out within the city. This developmental paper sets out a project to explore these themes

    Quantitative analysis of ERG expression and its splice isoforms in formalin-fixed, paraffin-embedded prostate cancer samples: Association with seminal vesicle invasion and biochemical recurrence

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    © American Society for Clinical Pathology. Objectives: The proto-oncogene ETS-related gene (ERG) is consistently overexpressed in prostate cancer. Alternatively spliced isoforms of ERG have variable biological activities; inclusion of exon 11 (72 base pairs [bp]) is associated with aggressiveness and progression of disease. Exon 10 (81 bp) has also been shown to be alternatively spliced. Within this study, we assess whether ERG protein, messenger RNA (mRNA), and ERG splice isoform mRNA expression is altered as prostate cancer progresses. Methods: Detection of the TMPRSS2-ERG fusion was done using direct methods (reverse transcription polymerase chain reaction [PCR] and fluorescence in situ hybridization) and indirect methods for ERG mRNA and protein expression using quantitative PCR and immunohistochemistry, respectively. A linear equation method was used to quantitatively determine relative proportions of ERG variants (ERG72/Δ72, ERG81/Δ81) for each sample. Results: ERG mRNA and protein expression is increased in patients with advanced prostate cancer, with higher levels of ERG expression significantly associated with seminal vesicle invasion (stage pT3b) and biochemical recurrence. Genes involved in cell migration and invasiveness (matrix metalloproteinase 7, osteopontin, and septin 9) are increased in prostate cancers that overexpress ERG. In addition, there is a clear indication of increased retention of exons 10 and 11 in prostate cancer. Conclusions: Analysis of ERG and its variants may be valuable in determining prognosis and development of prostate cancer

    Thermoresponsive Gels

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    An invited review and relates to the responsive gel used in the "artificial pancreas" work og INsmart, DMU. This article is an Open Access journal.Thermoresponsive gelling materials constructed from natural and synthetic polymers can be used to provide triggered action and therefore customised products such as drug delivery and regenerative medicine types as well as for other industries. Some materials give Arrhenius-type viscosity changes based on coil to globule transitions. Others produce more counterintuitive responses to temperature change because of agglomeration induced by enthalpic or entropic drivers. Extensive covalent crosslinking superimposes complexity of response and the upper and lower critical solution temperatures can translate to critical volume temperatures for these swellable but insoluble gels. Their structure and volume response confer advantages for actuation though they lack robustness. Dynamic covalent bonding has created an intermediate category where shape moulding and self-healing variants are useful for several platforms. Developing synthesis methodology—for example, Reversible Addition Fragmentation chain Transfer (RAFT) and Atomic Transfer Radical Polymerisation (ATRP)—provides an almost infinite range of materials that can be used for many of these gelling systems. For those that self-assemble into micelle systems that can gel, the upper and lower critical solution temperatures (UCST and LCST) are analogous to those for simpler dispersible polymers. However, the tuned hydrophobic-hydrophilic balance plus the introduction of additional pH-sensitivity and, for instance, thermochromic response, open the potential for coupled mechanisms to create complex drug targeting effects at the cellular level
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