3,474 research outputs found
Structure And Function Of The Src Gene Of Rous Sarcoma Virus And The Human Cellular Src Gene
The Rous sarcoma virus (RSV) src gene (v-src) is one of that most extensively studied oncogenes, yet the mechanism by which it transforms virus-infected cells remains unsolved. The study of mutants of RSV provides considerable information on the function of the v-src protein (p60(\u27v-src)).;Characterization of the chicken cellular counterpart of the v-src gene (c-src) has provided clues as to the alterations required to produce an oncogene from a normal cellular gene (proto-oncogene). Characterization of the human c-src gene will be useful for future studies aimed at detecting possible human c-src alterations associated with human neoplastic disorders.;The nucleotide sequence of the 3\u27 three-quarters of a molecularly cloned human c-src gene was determined. This region of the c-src gene encodes the tyrosine kinase domain of p60(\u27c-src) and corresponds to exons 4 through 12 of the chicken c-src gene. Human c-src is very strongly conserved with respect to the chicken c-src gene; 90% nucleotide homology and 98% amino acid homology exists between human and chicken c-src. The exon sizes and the locations of the exon-intron boundaries are identical in human and chicken c-src. Sequences within introns are not conserved, and most of the introns of human c-src are much larger than the corresponding chicken c-src introns.;The strong amino acid conservation of this region of p60(\u27c-src) of species as divergent as humans and chickens suggests that this portion of p60(\u27c-src) specifies one or more functional domains that are of great importance to some aspect of normal cellular growth or differentiation.;The nature of the lesions in three fusiform mutants (WO101, WO201, and tsST529) of the Schmidt-Ruppin strain of RSV was determined by molecular cloning and DNA sequencing. WO101, WO201, and tsST529 all contained an in frame deletion in the v-src region coding for amino acids 116-140 of p60(\u27src). The deleted segment is flanked by consensus splice donor and acceptor sequences and contains an appropriately positioned branchpoint acceptor consensus sequence, suggesting that the deletion occurred through an aberrant RNA splicing event. These results suggest that a protein domain within the N-terminal 1/3 of p60(\u27v-src) is important for controlling morphological parameters of transformation in RSV-infected cells
Narconon, Scientology, and the Battle for Legitimacy
This article provides an historical description and analysis of Scientology’s controversial drug treatment program, Narconon. Following scholarship by sociologist Terra Manca on Scientology’s pseudo-medicine, I argue that Scientology initially claimed its program to be part of its religion, but eventually dropped this claim as it attempted to get Narconon programs and teachings established in communities. I show, however, the intimate association between Scientology and Narconon courses, and present some of the evidence that the program lacks scientific validity—especially its Purification Rundown. Â
Perceptions of Effective Instruction in Community Colleges: A Student View
ABSTRACT Stephen K. Biermann PERCEPTIONS OF EFFECTIVE INSTRUCTION IN COMMUNITY COLLEGES: A STUDENT VIEW This qualitative study was designed to identify key elements of effective instruction as perceived by community college students. Since the majority of research pertaining to effective instruction has been primarily conducted using a quantitative format, it is important to consider other methodologies for future research. The use of qualitative research helped capture student dialogue in its fullest, unhindered by the constraints of a survey tool or scale. The students involved in the study voluntarily participated in either individual interviews or focus groups and commented upon various aspects of collegiate instruction, including direct instruction methodologies, instructional enthusiasm, and the use of instructional technology. A moderator conducted each of the nine individual interviews and three focus groups required to research the topic. Forty-four students from three community colleges participated in the study, with three individual interviews and a focus group conducted at each community college campus. Participants in the study were required to have a limited amount of community college experience. The individual interviews and focus groups were recorded and later transcribed. Together with notes taken by the moderator, the transcriptions were analyzed and themes were identified through the use of a qualitative data software package. The emerging themes allowed the researcher to draw significant conclusions or theories concerning the community college student perspective of effective instruction. The research indicated that students overwhelmingly found instructional enthusiasm to be the most effective instructional method. While the direct instruction model was also reported as significant, other factors such as the use of instructional technology were viewed as insignificant
Developing proteomics approaches for identifying new, redox-regulated proteins
Abstract only availableFor many years it was thought that hydrogen peroxide was only a toxic substance to cells. However, recent work has revealed that hydrogen peroxide can be utilized by organisms as a cellular signaling molecule. Hydrogen peroxide has the ability to react with proteins involved in signal transduction causing the activity of these proteins to be turned on or off. One such example is protein tyrosine phosphatase 1B (PTP1B) whose enzymatic activity is turned off by reacting with hydrogen peroxide. A cysteine residue in the active site of PTP1B is oxidized by hydrogen peroxide to form a sulfenic acid which then reacts with a neighboring amide nitrogen in the protein backbone to form a cyclic sulfenamide. The formation of this heterocycle causes PTP1B to lose its activity. In order to discover new proteins that are oxidatively regulated by hydrogen peroxide, chemical tools for selective detection of cyclic sulfenamide residues in cellular probing need to be developed. We describe results obtained using simple chemical models to identify reagents that have the ability to selectively tag protein derived sulfenamide residues.Life Sciences Undergraduate Research Opportunity Progra
Electroblotting onto activated glass. High efficiency preparation of proteins from analytical sodium dodecyl sulfate-polyacrylamide gels for direct sequence analysis
We have developed a new method for the isolation of proteins for microsequencing. It consists of electrophoretic transfer (electroblotting) of proteins or their cleavage fragments onto activated glass filter paper sheets immediately after separation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The proteins are immobilized on the glass fiber sheets by ionic interactions or by covalent attachment. A wide range of proteins can be prepared in this fashion with no apparent restriction due to solubility, size, charge, or other intrinsic properties of the proteins. As little as 50 ng of the transferred proteins can be detected using Coomassie Blue or fluorescent dye staining procedures and even smaller amounts of radiolabeled proteins by autoradiography. After detection, the protein- containing bands or spots are cut out and inserted directly into a gas- phase sequenator. The piece of glass fiber sheet acts as a support for the protein during the sequencing. Amounts of protein in the 5- to 150- pmol range can be sequenced, and extended runs can be obtained from the blotted samples because of improved stepwise yields and lower backgrounds. The method has been successfully applied to the sequencing of a variety of proteins and peptides isolated from one-dimensional and two-dimensional polyacrylamide gels
Substantial envelope-specific CD8 T-cell immunity fails to control siv disease
AbstractIt is unknown which HIV proteins to target by vaccination in order to generate the most effective CD8 T-cell immunity. We recently immunized SIVmac251-infected pigtail macaques with Gag peptides or a cocktail of peptides spanning all SIV proteins, including SIV Env. High-level SIV Env-specific CD8 T-cell responses were generated and 7 novel Env-specific CD8 T-cell epitopes in 10 animals were mapped. Env-specific CD8 T-cell responses were significantly inferior to Gag-specific responses, and no better than unvaccinated control animals, in the control of SIV replication and prevention of disease. Escape mutations emerged within several Env-specific CTL epitopes, suggesting at least some pressure imparted by the Env CTL responses, but this did not correlate with significantly reduced SIV replication. We conclude Env-specific CTL may not be the most effective response to induce by vaccination
The formation of cysteine-tyrosine crosslinks via a sulfenic acid intermediate [abstract]
Abstract only availableCysteine residues in proteins are readily oxidized to sulfenic acids. Sulfenic acids, in turn, can act as potent electrophiles that have been observed to form intrastrand protein crosslinks with neighboring amide or cysteine residues. Cysteine-tyrosine crosslinks have also been observed in proteins, but the mechanism(s) of their formation is not clear. In the work presented here we investigated the intramolecular reaction between a sulfenic acid and a tyrosine mimic. The results provide chemical evidence that sulfenic acids have the potential to forge intrastrand protein crosslinks with tyrosine residues in proteins.Life Sciences Undergraduate Research Opportunity Progra
Politiques de rage et narcissisme malin
Dans cet article, le trouble de la personnalitĂ© connu sous le nom de « narcissisme malin » est prĂ©sentĂ©. Ce concept est par la suite utilisĂ© pour expliquer la crĂ©ation, par le dirigeant d’un groupe, de politiques organisationnelles destinĂ©es Ă contrer les personnes qu’il considĂ©rait comme ennemies, mettant en Ă©vidence la rage narcissique Ă l’oeuvre. Notre argument est examinĂ© Ă la lumière d’une Ă©tude de cas dans laquelle il est dĂ©montrĂ© que le dirigeant a tentĂ© de discrĂ©diter les dĂ©tracteurs du groupe, transposant sa rage narcissique dans des politiques organisationnelles que des membres loyaux adoptaient pour lui. Ă€ l’aide d’observations psychologiques de la personnalitĂ© du chef et, par la suite, en dĂ©montrant comment celle-ci est Ă la source de politiques et d’actions socialement dĂ©viantes, nous espĂ©rons encourager les criminologues Ă examiner d’autres groupes en appliquant des thĂ©ories semblables.In this article, a personality disorder known as “malignant narcissism” is presented. This notion is then used to explain the creation of organizational policies against perceived enemies that reflected this narcissistic rage. We illustrate our argument by the analysis of a case study in which it is shown that the leader attempted to discredit the detractors of the group, thus transposing the narcissistic rage into organizational policies that loyal members enacted on his behalf. By using psychological insights about the leader’s personality, and then showing how that personality translated into socially deviant policies and actions, we hope to encourage criminologists to examine other groups by applying similar theories.En este artĂculo presentamos el trastorno de la personalidad denominado “narcisismo maligno”. Este concepto es a continuaciĂłn utilizado para explicar la creaciĂłn, por parte del dirigente de un grupo, de polĂticas organizacionales destinadas a contrarrestar a las personas consideradas por Ă©l como enemigas y que ponen de manifiesto su ira narcisista. Nuestra argumentaciĂłn es examinada a la luz de un estudio de caso en el que se demuestra que el dirigente intentĂł desacreditar a los detractores del grupo, trasfiriendo su ira narcisista a polĂticas organizacionales que fueron adoptadas por miembros leales a la organizaciĂłn. Gracias a observaciones psicolĂłgicas de la personalidad del lĂder y, más adelante, demostrando cĂłmo su personalidad está en la base de polĂticas y acciones socialmente desviantes, esperamos alentar a los criminĂłlogos a examinar otros grupos aplicando teorĂas similares
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