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Complex sphingolipid involvement in the expression of CYP1A1 activity in 3-methylcholanthrene-exposed HEPG2 cells, 2001
No full textPolycyclic aromatic hydrocarbons (PAHs), complex organic molecules that are the by-products of carbon-based fuel combustion, are carcinogenic upon biotransformation in the body. Cytochrome P450 1A1 (CYP1A1) is part of the enzyme system primarily responsible for the metabolism and biotransformation of PAHs in humans. In HepG2 cells (a human hepatoma cell line), it has been established previously in this laboratory that 3-methylcholanthrene (MC), a PAH, induces CYP1A1 activity 20 to 30 fold over control values. Also in those studies, MCs ability to induce this activity was significantly reduced by compounds that inhibit the synthesis of complex sphingolipids. However, addition of the synthetic short-chain sphingolipid C2-ceramide after inducer and inhibitor treatment restored CYP1A1 inducibility. This produced the current laboratory hypothesis that complex sphingolipids are involved in the signal transduction pathway used by MC to induce CYP1A1 activity. This research investigated the role that sphingolipids play in the inducibility of CYP1A1 by MC. Initially, the induction of CYP1A1 was examined by MC as a transcriptional event in these cells. Western blot analysis was used to determine whether CYP1A1 protein amounts fluctuate with CYP1A1 activity per the treatments used. Further studies included quantitative real-time reverse transcriptase PCR to quantitate the amount of CYP1A1 mRNA that resulted from each treatment. It was found that the action of the inhibitor of sphingolipid synthesis seems to be dependent on the presence of a heavy metal. It was also found that C2-ceramide, the prototype complex sphingolipid used, causes synergistic induction of CYP1A1 enzyme activity and that this synergism apparently results from actions at the level of the gene. Thus, it can be concluded that complex sphingolipids are involved in the transcriptional regulation of CYP1A1 expression
A survey of microcomputer usage and the perceptions of special educators in the instruction of mildly handicapped students within selected school systems of Georgia, 1986
Get PDFRATIONALE The purpose of the study was to survey the use of microcomputers as instructional assisted tools in the education of mildly handicapped students from selected school systems of Georgia. Specifically, the study addressed the following issues: (1) identified instructional uses of microcomputers in special education; (2) areas of exceptionality wherein instructional micro computer usage is evidenced; (3) perceptions of special educators toward microcomputer applications; and (4) future implications. SIGNIFICANCE The study will greatly expand the literature base and identify factors related to the use of microcomputers in the instructional process of educating mildly handicapped students. METHODS AND PROCEDURES Data for the study were generated from Directors of Special Education and Teachers of Mildly Handicapped Students from selected public school sys tems of Georgia. The chief data collection method used was the questionnaire with the interview/participant observation technique being secondary. The question naire used was a modified version of the instrument developed in 1982 by Henry Jay Becker to obtain data for his study, "School Uses of Microcom puters." Items for the revised instrument addressed demographic, usage and perception information. Both descriptive and inferential statistical procedures were used to analyze the data. Sections I and II of the questionnaire stimulated cate gorical data which produced percentages. The Chi-square statistical method at the .05 level was used to determine the statistically significant dif ference of the nominal data and to test one hypothesis. The Analysis of Variance statistical method was used at the .05 level to accept or reject five of the hypotheses. The secondary method of data collection involved the interview/partici pant observation methods. Items for the interview questions and the observa tion checklist were original. Sites for the field research were randomly selected to include visitations to the three different size school systems based on student population. Data for this phase of the study were reported in case studies. RESULTS The findings from the study reveal from a broad perspective that Direc tors of Special Education and Teachers of Mildly Handicapped Students demon strated great support of microcomputer usage in the instruction of mildly handicapped students. Special educators found the most productive use of this strategy in drill and practice and tutorial dialog activities. The area of mathematics was considered strongest with language arts being second rela tive to fundamental instructional use. Most computer time was scheduled during class periods. Strengths in the instructional applications included individualization, alternative approaches to learning, provisions for immediate feedback, flexi bility in management, increased student/teacher contact, student motivation, and increased student attention span. Problemmatic concerns include: limited and incompatible software, inadequate inservice, student/computer ratios and human interaction. The .05 confidence level was used to determine statistical significance. The null hypotheses formulated and tested on the variable groups were accepted at the .05 level. CONCLUSIONS Special education administrators (directors/coordinators) and teachers of mildly handicapped students strongly support the use of microcomputers as instructional assisted tools in the education of mildly handicapped students. Increasing use and versatility are evidenced; however, expanded efforts are needed for budgetary support, staff development, time management and sched uling. As improvements are made based on continued research the use of this technology will continue to enhance the educational opportunities of handi capped students
Detection of codon usage patterns for backtranslation using a neural network, 1998
Get PDFA neural network (NN) was trained on amino and nucleic acid sequences to test the NNs ability to predict the correct codon given only an amino acid sequence. Different network configurations were used with varying numbers of input neurons that represented amino acids and a constant representation for the nucleic acid. A multi-layer backpropagation network of one hidden layer with 5 to 9 neurons was used. In the best-trained network, 93% of the overall bases, 85% of the degenerate bases, and 100% of the fixed bases were correctly predicted. The training set was composed of up to 60 human sequences in a window of up to 25 codons at the coding sequence start site. Different input configurations for amino acid representations were designed and evaluated for usage in a large scale NN. This genetic data analysis effort will assist in understanding human gene structure. Benefits include computational tools that could predict more reliably the backtranslation of amino acid sequences useful for Degenerate PCR cloning, and may assist the identification of human gene coding sequences (CDS) from open reading frames in DNA databases
Human promoter characterization, 2010
No full textThe basic-helix-loop-helix (bHLH) protein family plays an innate role in cellular activities. A pivotal member of this family, the Inhibitor of differentiation (Id) proteins, is linked to cell proliferation, differentiation, and tumorigenesis via inhibiting the DNA binding of bHLH proteins. There are four isoforms of Id genes - Id1-4 are uniquely expressed. In prostate cancer cells, Id3 is up-regulated and targets cellular proliferation and metastasis. However, the mechanism that triggers Id3 expression in prostate cancer is unknown. Therefore, a series of experiments were performed in order to investigate the transcription factors that regulate the expression of Id3 promoter in prostate cancer. The proximal 1 kb human Id3 promoter was characterized and validated by a combination of in silico and in vitro approaches. Collective results led to the identification of YY 1, C/EPBa and C EPBb as putative transcription factors that could regulate Id3 promoter in prostate cancer. It is believed that further in depth studies of these transcription factors will lead to the identification of the underlying molecular mechanism that regulates Id3 expression in prostate cancer
An exploratory study of factors that contribute to decision making of African American adolescent females to engage in sexual behavior, 1998
No full textThe purpose of this study was to explore factors that contribute to decision making of African American adolescent females to engage in sexual behaviors. This study was conducted in Atlanta, Georgia, Fulton County at a metropolitan high school. An exploratory research design was utilized. A self-administered 78-item sexual decision making questionnaire was administered to the population of 30 African American adolescents who were currently pregnant and those who had previously delivered. A Chi-square analysis was employed to analyze the significant relationship of the hypotheses. It was concluded that there were significant statistical relationships between sexual decision making and age, onset of menses, partners' reaction, and ability/desire to be a parent
The mass communications behavior of the residents of census tract F-37, Atlanta, Georgia, 1954
No full textThe teaching of arithmetic in selected elementary schools of Meriwether County, Georgia, 1963
Get PDFBirth order : a social work examination of predicting resilience, 2017
No full textThis study examines the order in which an individual is born and how, when examining birth order, does the psychological make- of the first, middle and last child born influence how the individual will be later in their life. This study was based on two premises: (1) In social work there is not a need to focus on birth order, classifying it solely as a matter of psychology; (2) When a child is born, they are given an order among their siblings that provides them with a set of experiences, roles, and responsibilities that attribute the child in the given birth order. A systematic review was used to analyze data gathered on the contributions of sibling relationships, and the psychological make-up of the first, middle and last born child, and how each can predict the resilience of the individual