Biochemistry Commons^™

Glucocorticoid Regulation Of Insulin Like Growth Factor Binding Protein-5 Gene Transcription In Human Osteoblasts, Xiaoying Wang

Loma Linda University Electronic Theses, Dissertations & Projects

Glucocorticoids (GCs) inhibit bone formation in vivo and inhibit osteoblast proliferation and collagen synthesis in vitro. These effects may be mediated by alterations in the insulin-like growth factor (IGF) system. In the present study of normal human osteoblast-like (HOB) cells, we tested the hypothesis that dexamethasone (Dex) inhibits the expression of IGF binding protein-5 (IGFBP-5). Dex decreased IGFBP-5 mRNA levels to 54% of control after 4 hr. Dex did not modify the decay of IGFBP-5 mRNA in transcriptionally arrested osteoblast cells. Dex decreased IGFBP-5 hnRNA levels to 67% of control after 2 hr, and the activity of the human IGFBP- …

Studies On The Purification And Role Of Igfbp-5 Protease In Bone, H. Garrett Rush Thompson

Loma Linda University Electronic Theses, Dissertations & Projects

Osteoporosis is a disease characterized by low bone density and deterioration of mineralized bone leading to enhanced susceptibility to fracture. Several growth factors have been implicated in the coupling of formation to resorption during the bone remodeling process. The net bone forming activity of many growth factors has prompted numerous studies focused on the regulation of osteoblast cell proliferation, differentiation and activity. The current study focuses on the insulin-like growth factor (IGF) system, an important growth factor system involved in the regulation of bone formation and bone resorption.

IGF binding protein -5 (IGFBP-5), the most abundant IGF binding protein in …

Induction Of Apoptosis In Human Prostate Cancer Cells By Resveratrol, Gary Zulfikar Morris

Chemistry & Biochemistry Theses & Dissertations

Recently attention has been brought to trans-resveratrol's {TR) anticancer activity, as determined through a number of cultured cancer cell models. This activity was attributed to TR behaving as an estrogen, and the orientation of TR' s hydroxyl groups. Based on this work it was of interest to determine whether TR would also be toxic in prostate cancer cells; if toxic, did TR induce necrosis or apoptosis in the cells; was it toxic through hormone mediated pathways; and were TR's hydroxyl groups responsible for its biological activity. To this end, cellular viability was assessed in two different prostate cancer cell …

Identification And Characterization Of The Cis-Acting Elements Around The Murine Cd4 Cnhancer, Xin Dong

Loma Linda University Electronic Theses, Dissertations & Projects

The cluster determinant 4 (CD4) molecule is a transmembrane glycoprotein. CD4 is essential for normal T helper cell function and plays an important role in T cell development and activation. CD4 is encoded by a single gene located on chromosome 6 in the mouse and chromosome 12 in the human. Both human and murine CD4 genes are divided into ten exons spanning more than 25 kb and have a large non-coding region in the first and third intron. CD4 gene expression is controlled primarily at the transcriptional level during T cell development and activation.

An enhancer has been identified approximately …

Mechanistic Characterization Of The Mitochondrial Type I Dna Topoisomerase And A Study Of Genes Containing Type I Dna Topoisomerase-Related Domains, Jaydee Dones Cabral

Theses and Dissertations in Biomedical Sciences

The mitochondrial type I DNA topoisomerase (mt-topo I) serves an important function in the mitochondrion by relaxing mtDNA supercoils to allow for replication of the mitochondrial genome as well as for gene expression. The mt-topo I's role in essential processes, such as replication and transcription, makes it an ideal candidate as a target for antitumor or antifungal drugs. To gain further insight into mt-topo I mechanism, a cleavage assay and drug inhibition studies were performed. As well, a search for the mt-topo I gene or genes containing type I topoisomerase-related domains was conducted. To characterize the mt-topo I mechanism, the …

Investigations On The Use Of Ion Mobility Spectrometry For Clinical Chemistry Applications, Henri Parson Patten

Theses and Dissertations in Biomedical Sciences

The major objective of this research is to examine ion mobility spectrometry as a rapid screening tool for specific application to clinical chemistry research and laboratory use. Methodology was developed for target analytes representing several classes of physiologically active substances, including anesthetics, illicit drugs, and their metabolites. The IMS characteristics of animal tissues and other compounds such as amino acids and proteins were determined. Quality assurance and control procedures were developed for specific quality data objectives. Criteria were established relating to use of IMS for assessing the precision and accuracy of data, qualitative screening, and semi-quantitative analyses.

It was found …

Identification And Characterization Of Control Elements Within The Murine Cd4 Gene, Zhong Deng

Loma Linda University Electronic Theses, Dissertations & Projects

The control of CD4 gene expression is essential for T lymphocyte development. Since the molecular mechanism for the control of CD4 gene expression during T cell development had not been elucidated, a study of the factors that control CD4 gene expression may lead to further. Toward these goals, we have made a series of recombinant DNA constructs to define the cis-acting transcriptional control elements in the murine CD4 locus that control CD4 gene expression during T cell development. In this study, we have identified multiple cis-acting control elements, which are critical for regulating the expression of the murine …

Telomerase Activity In Prostatic Fluid And Tissue As A Marker For Prostate Cancer, Zhilian Wang

Loma Linda University Electronic Theses, Dissertations & Projects

Telomerase is a ribonucleoprotein enzyme that is able to add telomeric repeats to the ends of eukaryotic DNA to stabilize chromosomes. Telomerase is active in germline cells, stem cells and tumor cells, but not in most human somatic cells. In this study we report the extended use of the Telomeric Repeat Amplification Protocol (TRAP) assay for the detection of telomerase activity in prostate needle biopsy specimens and freshly collected prostatic fluid. Clinical application of a newly developed PCR-ELISA telomerase assay method is also evaluated. Multiple sextant needle biopsy specimens from 56 subjects and prostatic secretion specimens from 72 subjects, with …

Comparison Of The Mutant Frequency And Mutation Spectra Of Three Non-Genotoxic Carcinogens Oxazepam, Phenobarbital, And Wyeth 14,643 At The Λcii Locus In Big Blue Transgenic Mice, Vijaypreet K. Singh

Honors Theses

No abstract provided.

Characterization Of Human T-Cell Leukemia Virus 1 Reverse Transcriptase, Pinky Gundayao Agbuya

Theses and Dissertations in Biomedical Sciences

Human T-cell leukemia virus 1 (HTLV-1) is a type C human retrovirus which has been the causative agent of Adult T-cell leukemia. Replication of the retrovirus; requires a reverse transcriptase which converts the retroviral RNA into DNA which is later incorporated into the host's genome. Very little is known about the reverse transcriptase of HTLV-1. Researchers have attempted to purify HTLV-1 RT by isolating the enzyme from human cell lines. Because large amounts of protein could not be produced by this isolation method, the reverse transcriptase cannot be fully characterized. In this research, a recombinant protein expressed in E. coli …

The Influence Of Leptin On Metabolic Expenditure And Thermogenesis During Thyroid Hormone (T₃) Suppression In The Obese (Ob/Ob) Mouse, Brian Kimball Underhill

Theses Digitization Project

No abstract provided.

Applications Of The Atomic Force Microscope Within The Fields Of Haematology And Cytogenetics, Margaret O'Reilly-Crowley

Theses

Atomic force microscopy [AFM] has become a rapidly developing interdisciplinary field of research in recent years. The technique, including instrumentation and specimen preparation methods, is now more sophisticated and its application has increased dramatically. The key advantage of AFM is in providing three-dimensional images of samples imaged. Both size and shape of samples imaged can be obtained allowing their subsequent quantification. Red blood cells [RBCs] and chromosomes were imaged in this work. A brief overview of the current status of biomedical AFM, has been presented in the review.

Measurement of mean cell volume [MCV] of immobilised red blood cells with …

Cytotoxic T Cell Response To Influenza Vaccination In Older Adults, Caroline R. Letter

Chemistry & Biochemistry Theses & Dissertations

Influenza infections result in activation of cellular and humoral immune responses, leading to stimulation of cytotoxic T cells (CTL) and helper T cells with subsequent viral clearance.

By using an assay of granzyme B activity, the in vivo cellular-mediated immune response of old adults was found to be significantly decreased in comparison to young adults. The effect of aging on the CTL response was further investigated via enzyme-linked immunospot technique. A significant increase in number of virus-specific T cells occurred in older adults after vaccination, although the magnitude of the CTL response decreased in comparison to young adults. These data …