SEARCH · PubMed Health

Results for “Prime editing”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

100 records · Page 6Linked to original sources

PubMed1998

Effects of televised safety models on children's risk taking and hazard identification.

OBJECTIVE: To examine effects of televised safety models on children's willingness to take physical risks and their ability to identify injury hazards in common situations. METHODS: Sixty children, between the ages of five and eight years, were exposed to one of three TV stimulus programs: (1) a safety educational videotape, in which actors engaged in dangerous behavior, suffered injuries, and then enacted alternative safe behaviors; (2) an animated cartoon, which portrayed characters engaged in safety behaviors incidental to the main story line; or (3) the same cartoon program edited to omit the scenes depicting safety behavior. Children's willingness to take physical risks was measured before and after the TV stimulus by a series of pictorial child-relevant scenarios in which they could indicate the level of risk they would take. They also completed pretest and posttest measures of hazard identification, in which they were to identify injury hazards in several pictorial scenarios. RESULTS: Exposure to the safety educational videotape decreased children's willingness to take physical risks and increased their identification of injury hazards. Exposure to the animated cartoon with incidental safety components did not affect risk taking, but did increase ability to identify hazards. CONCLUSIONS: Findings are interpreted as evidence of observational learning and priming of thematically related knowledge by the television stimuli. Implications for safety educational curricula are discussed.

Analysis of Variance↗

PubMed1995

Site selection for Mars exobiology.

The selection of sites on Mars that have a high priority for exobiological research is fundamental for planning future exploration. The most immediate need is to identify targets for high resolution orbital imaging during the Mars Observer and Mars '94/'96 missions that can be used to refine site priorities for surface exploration. We present an objective approach to site selection whereby individual sites are selected and scored, based on the presence of key geological features which indicate high priority environments. Prime sites are those that show evidence for the prolonged activity of liquid water and which have sedimentary deposits that are likely to have accumulated in environments favorable for life. High priority areas include fluvio-lacustrine (stream-fed lake systems), springs, and periglacial environments. Sites where mineralization may have occurred in the presence of organisms (e.g. springs) are given high priority in the search for a fossil record on Mars. A systematic review of Viking data for 83 sites in the Mars Landing Site Catalog resulted in the selection of 13 as being of exobiological interest. The descriptions of these sites were expanded to address exobiological concerns. An additional five sites were identified for inclusion in the second edition of the MLSC. We plan to broaden our site selection activities to include a systematic global reconnaissance of Mars using Viking data, and will continue to refine site priorities for exobiological research based on data from future missions in order to define strategies for surface exploration.

Exobiology↗

PubMed2000

To die in one's prime: the story of Paul Wood.

Paul Wood, the leader of European cardiology during the mid-20th century, was internationally admired for his bedside teaching, clinical investigations, and an important textbook on cardiology. His studies, based on a unique quantitative approach to the grading and recording of clinical data, introduced cardiac physiology to the bedside, brought accuracy to the preoperative assessment of cardiac disease, and became the foundation for much of our current understanding about congenital and rheumatic heart disease and pulmonary hypertension. At the bedside, in front of a crowd of postgraduate students, registrars, and visitors, he was renowned for his showmanship and dazzling ability. His commanding personality--caustic, sarcastic, and combative--impressed many and offended some as he openly argued with himself and others to sleuth out the correct diagnosis. His 1950 textbook, Diseases of the Heart and Circulation, characterized by his lucid and personal style of writing and a fresh physiologic approach to cardiology, brought Wood worldwide recognition as the European authority on heart disease. The incessant demands to see patients, teach, and lecture, the burden of writing his third edition of the book, and his heavy smoking eventually took their toll. On July 13, 1962, at the age of 54, Paul Wood, the gale force wind of British cardiology and the inspiration and role model for many students, died quietly following a myocardial infarction. He left a legacy of great accomplishments as the transition figure between the old and modern era of cardiology.

Cardiology↗

PubMed2003

Multiple subphases of DNA repair and poly (ADP-ribose) synthesis in Chinese hamster ovary (CHO-K1) cells.

The two types of DNA synthesis as well as poly(ADP-ribose) biosynthesis were measured simultaneously in synchronized intact populations of CHO cells throughout the duration of S phase. Naturally occurring DNA fragmentation was detected by random primed oligonucleotide synthesis (ROPS assay). Fractions of synchronous cell populations were obtained by counterflow centrifugal elutriation. By gradually increasing the resolution of centrifugal elutriation multiple non-overlapping repair and replication peaks were obtained. The elutriation profile of DNA repair peaks corresponded to the DNA fragmentation pattern measured by ROPS assay. The number and position of poly(ADP-ribose) peaks during S phase resembled those seen in the DNA replication profile. Our results indicate that PAR synthesis is coupled to DNA replication serving the purpose of genomic stability.

Animals↗

PubMed2006

"Viral déjà vu" elicits organ-specific immune disease independent of reactivity to self.

Autoimmune diseases are often precipitated by viral infections. Yet our current understanding fails to explain how viruses trigger organ-specific autoimmunity despite thymic tolerance extending to many non-lymphohematopoietic self antigens. Additionally, a key epidemiological finding needs to be explained: In genetically susceptible individuals, early childhood infections seem to predispose them to multiple sclerosis (MS) or type 1 diabetes years or even decades before clinical onset. In the present work, we show that the innate immune system of neonatal mice was sufficient to eliminate an attenuated lymphocytic choriomeningitis virus (LCMV) from most tissues except for the CNS, where the virus persisted in neurons (predisposing virus). Virus-specific cytotoxic T cells (CTLs) were neither deleted nor sufficiently primed to cause disease, but they were efficiently triggered in adulthood upon WT LCMV infection (precipitating virus). This defined sequence of viral infections caused severe CNS inflammation that was histomorphologically reminiscent of rasmussen encephalitis, a fatal human autoimmune disease. Yet disease in mice was mediated by antiviral CTLs targeting an epitope shared by the precipitating virus and the predisposing virus persisting in neurons (déjà vu). Thus the concept of "viral déjà vu" demonstrates how 2 related but independently encountered viral infections can cause organ-specific immune disease without molecular mimicry of self and without breaking self tolerance.

Animals↗

PubMed1998

Effect of a 3'-->5' exonuclease with a proofreading function on the fidelity of error-prone DNA polymerase alpha from regenerating liver of aged rats.

A nuclease that releases noncomplementary nucleotides from the 3'-end of DNA was isolated and highly purified from rat liver extract. The d(T9-C) priming activities for DNA synthesis in vitro by DNA polymerases alpha and beta were recovered by the addition of this enzyme, which itself does not contain a DNA polymerase activity. This nuclease hydrolysed nucleotides from the 3'-end, but did not remove [32P]-labeled nucleotides from the 5'-terminus of specifically labeled DNA. Also, the reaction products released from the 3'-end of DNA were all mononucleotides. These results indicate that the exonuclease is a 3'-->5' exonuclease with properties the same as those of DNase VII from human placenta. Rat DNase VII requires 4 mM MgCl2 or 0.125 mM MnCl2 for maximum activity, and shows a pH optimum of 7.5. These optimal conditions are similar to those of DNA polymerases, and indicate that both rat DNase VII and DNA polymerases are able to act under same conditions. Non-complementary nucleotide incorporation by DNA polymerase alpha from aged rat has been observed during in vitro DNA synthesis on poly dA-dT10. The amount of this mis-incorporation is decreased by the coexistence of the 3'-->5' exonuclease, but not all errors are edited out. Thus, this rat DNase VII is suggested to play an important role in proofreading during DNA synthesis.

Aging↗

PubMed2005

Computer skills for the next generation of healthcare executives.

Students beginning a career in healthcare administration must possess an array of professional and management skills in addition to a strong fundamental understanding of the field of healthcare administration. Proficient computer skills are a prime example of an essential management tool for healthcare administrators. However, it is unclear which computer skills are absolutely necessary for healthcare administrators and the extent of congruency between the computer skills possessed by new graduates and the needs of senior healthcare professionals. Our objectives in this research are to assess which computer skills are the most important to senior healthcare executives and recent healthcare administration graduates and examine the level of agreement between the two groups. Based on a survey of senior healthcare executives and graduate healthcare administration students, we identify a comprehensive and pragmatic array of computer skills and categorize them into four groups, according to their importance, for making recent health administration graduates valuable in the healthcare administration workplace. Traditional parametric hypothesis tests are used to assess congruency between responses of senior executives and of recent healthcare administration graduates. For each skill, responses of the two groups are averaged to create an overall ranking of the computer skills. Not surprisingly, both groups agreed on the importance of computer skills for recent healthcare administration graduates. In particular, computer skills such as word processing, graphics and presentation, using operating systems, creating and editing databases, spreadsheet analysis, using imported data, e-mail, using electronic bulletin boards, and downloading information were among the highest ranked computer skills necessary for recent graduates. However, there were statistically significant differences in perceptions between senior executives and healthcare administration students as to the extent of computer skills required in areas such as word processing, graphics and presentation, spreadsheet analysis, using imported data, and working with local area networks (LANs).

Computer Literacy↗

PubMed2003

Induction of arthritis in SCID mice by T cells specific for the "shared epitope" sequence in the G3 domain of human cartilage proteoglycan.

OBJECTIVE: To study the immunologic function and determine the fine epitope structure of a synthetic peptide p135H ((2373)TTYKRRLQKRSSRHP) of the G3 domain of human cartilage proteoglycan (aggrecan), which contains a highly homologous sequence motif of the shared epitope (QKRAA), the most common sequence motif in HLA-DR4 alleles, which predispose humans to the development of rheumatoid arthritis (RA). METHODS: Synthetic p135 peptides with altered sequences were used for (hyper)immunization of arthritis-susceptible BALB/c mice and then challenged with a single dose of cartilage proteoglycan. Human p135 (p135H) and mouse p135 (p135M) synthetic peptides of the G3 domain of aggrecan were used to prime lymphocytes, which were then used for adoptive transfer of arthritis into "presensitized" SCID mice, determining cross-reactivity among p135 peptides and their analogous sequences, and generating T cell hybridomas. T cell hybridomas were also used for arthritis transfer into SCID mice and for characterizing the fine epitope structure of T cell receptor (TCR) and major histo-compatibility complex (MHC) binding sites of the immunogenic/arthritogenic p135H sequence. RESULTS: While p135H peptide-(hyper)immunized mice became sensitized, they developed arthritis only after injection of a single dose of cartilage proteoglycan aggrecan. An altered peptide sequence (p135H-AA) carrying the shared epitope motif (QKRAA) was as effective as the natural peptide p135H sequence for inducing arthritis. Mouse p135M-specific lymphocytes induced arthritis with a lower incidence, but synthetic peptides to Escherichia coli heat-shock protein (DnaJ) or HLA-DR4 allele (both having the shared epitope sequence with different flanking regions) were also positive. Fine epitope sequence recognition of an arthritogenic T cell hybridoma derived from p135H-primed lymphocyte population was determined. Interestingly, in the most central position, a basic amino acid triplet of p135H peptide was found to be the MHC-binding motif, whereas the flanking amino acids bound to the TCR. CONCLUSION: Peptide p135H, corresponding to the peptide sequence in the G3 domain of human cartilage proteoglycan aggrecan, is immunogenic/arthritogenic in BALB/c mice. Peptide p135H includes a highly homologous motif of the shared epitope, a sequence that is overrepresented in bacterial heat-shock proteins, envelope protein of human JC polyomavirus, and numerous HLA-DR4 alleles. Since the G3 domain of cartilage proteoglycan aggrecan with the p135 sequence is "lost" during the normal metabolic turnover of cartilage proteoglycan or in pathologic conditions, an antigenoriented T cell migration into joints of presensitized (susceptible) individuals may contribute to the organ-specificity of RA.

Adoptive Transfer↗

PubMed2006

Mapping the conformation of the nucleic acid framework of the T7 RNA polymerase elongation complex in solution using low-energy CD and fluorescence spectroscopy.

The bacteriophage T7 elongation complex is an excellent model system in which to characterize the fundamental steps of transcription. We have formed functional elongation complexes, by mixing preassembled and RNA-primed DNA "bubble" constructs with T7 RNA polymerase and by initiating transcription at promoters, and have monitored the low-energy CD and fluorescence spectra of pairs of 2-aminopurine residues that have been inserted at defined sites within the DNA and RNA scaffold of the complex. In this way, we have been able to probe specific changes in the local conformations of the bases and base-pairs at these positions as the elongation complex goes through the various steps of the nucleotide addition cycle. The advantage of using pairs of 2-aminopurine residues, inserted at defined nucleic acid positions, as probes, is that the rest of the complex is spectrally "transparent" at wavelengths >300 nm. Thus, by combining CD and fluorescence measurements we obtain both structural and dynamic information that applies uniquely at each position within the functioning complex. In this way, we have mapped the details of steps central to transcription, including the formation and translocation of the transcription bubble, the formation and unwinding of the RNA-DNA hybrid, the passage of the nascent RNA through the exit channel of the polymerase, and the events of the template-controlled NTP selection process that controls transcriptional fidelity. This approach defines specific structural aspects of the elongation process under physiological conditions, and can be extended to examine other key aspects of transcriptional regulation, such as termination, editing, pausing, etc., that involve conformational rearrangements within the nucleic acid framework of the transcription complex.

2-Aminopurine↗

PubMed2005

The pattern recognition receptor PTX3 is recruited at the synapse between dying and dendritic cells, and edits the cross-presentation of self, viral, and tumor antigens.

Pentraxins are soluble pattern recognition receptors with a dual role: protection against extracellular microbes and autoimmunity. The mechanisms by which they accomplish these tasks are not yet fully understood. Here we show that the prototypic long pentraxin PTX3 is specifically recruited at both sides of the phagocytic synapse between dendritic cells (DCs) and dying cells and remains stably bound to the apoptotic membranes (estimated half-time > 36 hours). Apoptotic cells per se influence the production of PTX3 by maturing DCs. When both microbial stimuli and dying cells are present, PTX3 behaves as a flexible adaptor of DC function, regulating the maturation program and the secretion of soluble factors. Moreover a key event associated with autoimmunity (ie, the cross-presentation of epitopes expressed by apoptotic cells to T cells) abates in the presence of PTX3, as evaluated using self, viral, and tumor-associated model antigens (vinculin, NS3, and MelanA/MART1). In contrast, PTX3 did not influence the presentation of exogenous soluble antigens, an event required for immunity against extracellular pathogens. These data suggest that PTX3 acts as a third-party agent between microbial stimuli and dying cells, contributing to limit tissue damage under inflammatory conditions and the activation of autoreactive T cells.

3T3 Cells↗