Synthetic biology is an interdisciplinary field that brings together engineering and biology concepts alongside the arts and social sciences to develop solutions to pressing problems in our world. The education of students entering this field has relied on a diverse set of pedagogical methods to accomplish this goal. One non-profit group, iGEM-the International Genetically Engineered Machine competition, has been a driver of students' awareness of synthetic biology for the last 20 years giving many young researchers their first experience in the field of synthetic biology.
View Article and Find Full Text PDFEngineered DNA will slow the growth of a host cell if it redirects limiting resources or otherwise interferes with homeostasis. Escape mutants that alleviate this burden can rapidly evolve and take over cell populations, making genetic engineering less reliable and predictable. Synthetic biologists often use genetic parts encoded on plasmids, but their burden is rarely characterized.
View Article and Find Full Text PDFEngineered DNA will slow the growth of a host cell if it redirects limiting resources or otherwise interferes with homeostasis. Populations of engineered cells can rapidly become dominated by "escape mutants" that evolve to alleviate this burden by inactivating the intended function. Synthetic biologists working with bacteria rely on genetic parts and devices encoded on plasmids, but the burden of different engineered DNA sequences is rarely characterized.
View Article and Find Full Text PDFIntroduction: Hypotension after deceased donor kidney transplant (DDKT) is a risk factor for delayed graft function (DGF) and poor graft survival (GS). We hypothesize that vasopressin use in hypotensive DDKT recipients (DDKTRs) to increase blood pressure (BP) reduces DGF rates and is safe without increasing mortality.
Methods: Group with vasopressin "study group" ( 45) was defined as DDKTRs between 2012 and 2017 who required vasopressin for hypotension systolic BP (SBP) <120 mm Hg or diastolic BP (DBP) <60 mm Hg.
Introduction: Nondirected donation (NDD) of the kidneys is a growing practice where donors who do not have any genetic or emotional relationship are selected to donate to a wide variety of recipients with a range of selection criteria and decisions which are left up to individual transplant centers.
Methods: We review all adult living kidney donor-recipient (DR) pairs and outcomes from NDDs who were recorded in United Network for Organ Sharing (UNOS) database as code 10 (anonymous) from October 1997 to September 2017 for demographics and outcomes.
Results: A total of 2174 DR pairs were identified.
Introduction: A critical question facing transplant programs is whether, when, and how to safely accept living kidney donors (LKDs) who have recovered from COVID-19 infection. The purpose of the study is to understand current practices related to accepting these LKDs.
Methods: We surveyed US transplant programs from 3 September through 3 November 2020.
Caffeine and other methylxanthines are stimulant molecules found in formulated beverages, including sodas and energy drinks, and in brewed beverages, such as coffee and teas. Previously, we developed a bioassay for caffeine that involves monitoring the growth of a mutant of defective in guanine biosynthesis. When supplemented with a plasmid expressing the genes for an -demethylation pathway from CBB5, these bacteria demethylate caffeine (1,3,7-trimethylxanthine) and other methylxanthines into xanthine, which is then converted into guanine to support cell growth.
View Article and Find Full Text PDFMobile genetic elements drive evolution by disrupting genes and rearranging genomes. Eukaryotes have evolved epigenetic mechanisms, including DNA methylation and RNA interference, that silence mobile elements and thereby preserve the integrity of their genomes. We created an artificial reprogrammable epigenetic system based on CRISPR interference to give engineered bacteria a similar line of defense against transposons and other selfish elements in their genomes.
View Article and Find Full Text PDFBy introducing engineered tRNA and aminoacyl-tRNA synthetase pairs into an organism, its genetic code can be expanded to incorporate nonstandard amino acids (nsAAs). The performance of these orthogonal translation systems (OTSs) varies greatly, however, with respect to the efficiency and accuracy of decoding a reassigned codon as the nsAA. To enable rapid and systematic comparisons of these critical parameters, we developed a toolkit for characterizing any Escherichia coli OTS that reassigns the amber stop codon (TAG).
View Article and Find Full Text PDFOutcomes of kidney re-transplant recipients (RTR) were compared to primary recipients (FTR) from paired donor kidneys. Organ Procurement and Transplantation Network (OPTN) database was used to identify deceased donors (n = 6266) who donated one kidney to an RTR and the mate kidney to an FTR between January 2000 to December 2010. As compared to FTR, RTR were younger (45 vs.
View Article and Find Full Text PDFRiboswitches are shape-changing regulatory RNAs that bind chemicals and regulate gene expression, directly coupling sensing to cellular actuation. However, it remains unclear how their sequence controls the physics of riboswitch switching and activation, particularly when changing the ligand-binding aptamer domain. We report the development of a statistical thermodynamic model that predicts the sequence-structure-function relationship for translation-regulating riboswitches that activate gene expression, characterized inside cells and within cell-free transcription-translation assays.
View Article and Find Full Text PDFAngiosarcomas are extremely rare malignant tumors of vascular origin. We describe a 63-year-old recipient after a kidney transplant who had an angiosarcoma in the lower extremity that presented after new-onset deep venous thrombosis and was not associated with any fistula. There was rapid progression to metastasis and death.
View Article and Find Full Text PDFUnwanted evolution can rapidly degrade the performance of genetically engineered circuits and metabolic pathways installed in living organisms. We created the Evolutionary Failure Mode (EFM) Calculator to computationally detect common sources of genetic instability in an input DNA sequence. It predicts two types of mutational hotspots: deletions mediated by homologous recombination and indels caused by replication slippage on simple sequence repeats.
View Article and Find Full Text PDFOur aim was to study the long-term outcomes of all transplant recipients who underwent angiography for suspected TRAS at our institution. The patients were divided into TRAS+ve and TRAS-ve groups based upon angiographically confirmed results. TRAS was confirmed in 58.
View Article and Find Full Text PDFPost-kidney transplant recurrence of focal segmental glomerulosclerosis (FSGS) is a major problem. AT1R is expressed on podocyte; its expression is elevated in the proteinuric state. Using an ELISA, we tested pre-transplant sera of 28 patients with history of idiopathic FSGS for anti-AT1R levels and serum soluble urokinase-type plasminogen activator receptor (suPAR) as a biomarker for risk of recurrence of FSGS.
View Article and Find Full Text PDFRiboswitches are sequences of RNA that control gene expression via RNA-ligand interactions, without the need for accessory proteins. Riboswitches consist of an aptamer that recognizes the ligand and an expression platform that couples ligand binding to a change in gene expression. Using in vitro selection, it is possible to screen large (∼ 10(13) members) libraries of RNA sequences to discover new aptamers.
View Article and Find Full Text PDFIntroduction: Living donor evaluation involves imaging to determine the choice of kidney for nephrectomy. Our aim was to study the diagnostic accuracy and correlation between CT-based volume measurements and split renal function (SRF) as measured by nuclear renography in potential living donors and its impact on kidney selection decision.
Methods: We analyzed 190 CT-based volume measurements in healthy donors, of which 65 donors had a radionuclide study performed to determine SRF.
Kidney transplantation faces many challenges not the least of which is the presence of pre-formed HLA antibodies. At our institution, we have used a combination of methods to immunomodulate sensitized patients. Most recently, this has been attempted with a combination of immunoglobulin (IVIG) and rituximab (Rituxan; Genetech, CA, USA).
View Article and Find Full Text PDFThe significance of donor-specific antibodies (DSA) is not well known in the setting of pancreas transplantation. Since December 2009, we prospectively followed pancreas transplant patients with single-antigen-luminex-bead testing at one, two, three, six, and then every six months for the first two yr. Thirty-five of the 92 patients that underwent pancreas transplantation (13 pancreas-alone [PTA], 20 with a kidney [SPK], and two after a kidney [PAK]) agreed to participate in study.
View Article and Find Full Text PDFKidney dysfunction is a recognized complication after non-renal solid organ transplantation, particularly after intestinal transplant. In our study, we reviewed data on 33 multivisceral transplant (MVT)- and 15 isolated small bowel (ISB)-transplant patients to determine risk factors for kidney dysfunction. Kidney function was estimated by modified diet in renal disease (MDRD) and Schwartz formula for adults and children, respectively.
View Article and Find Full Text PDFMore than half of the simultaneous pancreas kidney transplant (SPK) patients afflicted with BK virus nephropathy (BKVN) lose their kidney allograft. Fear of pancreatic rejection limits the ability to reduce immunosuppression; this may result in inadequate treatment of BKVN. This single-center retrospective review included 138 SPK patients who underwent periodic BKV screening and were managed with IS reduction alone as a treatment of choice for BKVN.
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