Browsing by Subject "Calcium"
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Item A Bone and Buccal Sensitivity Study Comparison and Stability Study using the PowerPlex[R] Fusion 6C System(2018-05) McDaniel, Ethan L.; Warren, Joseph E.; Planz, John V.; Krishnamoorthy, Raghu R.; Gaydosh-Combs, LauraA validation study, a bone sensitivity study and a stability study were performed using the PowerPlex[R] Fusion 6C System. These studies were performed on a 7500 Real-Time PCR System, 9700 GeneAmp Thermocycler and 3500xL Genetic Analyzer. Buccal DNA was used to develop a method to analyze the DNA profiles gathered during the bone sensitivity study and stability study. DNA profiles for specific concentrations of DNA in solution were obtained during the bone sensitivity study. The stability study showed profiles exhibiting the effects of metal PCR inhibitors being introduced to the DNA extract solutions. Full profiles were obtained for calcium concentrations less than 7.35 mM, while the instrument was fully inhibited for copper concentrations between 0mM and 7.35 mM. Based on the limited data, the PowerPlex Fusion 6C System cannot tolerate copper when present in DNA solutions; whereas, calcium may be tolerated as an inhibitor up to 7.35mM.Item Association of Magnesium Intake with Liver Fibrosis among Adults in the United States(MDPI, 2021-01-02) Tao, Meng-Hua; Fulda, Kimberly G.Liver fibrosis represents the consequences of chronic liver injury. Individuals with alcoholic or nonalcoholic liver diseases are at high risk of magnesium deficiency. This study aimed to evaluate the association between magnesium and calcium intakes and significant liver fibrosis, and whether the associations differ by alcohol drinking status. Based on the National Health and Nutrition Examination Survey (NHANES) 2017–2018, the study included 4166 participants aged >18 years who completed the transient elastography examination and had data available on magnesium intake. The median liver stiffness of 8.2 kPa was used to identify subjects with significant fibrosis (≥F2). The age-adjusted prevalence of significant fibrosis was 12.81%. Overall total magnesium intake was marginally associated with reduced odds of significant fibrosis (p trend = 0.14). The inverse association of total magnesium intake with significant fibrosis was primarily presented among those who had daily calcium intake <1200 mg. There were no clear associations for significant fibrosis with calcium intake. Findings suggest that high total magnesium alone may reduce risk of significant fibrosis. Further studies are needed to confirm these findings.Item Calcium Sensitivy of β-cell Transcription Factor Binding to an Insulin Enhancer(1998-06-01) Scott, Gary Frank; Easom, Richard; Lacko, Andras G.; Wu, Ming-ChiGary Frank Scott, Calcium Sensitivity of β-cell Transcription Factor Binding to an Insulin Enhancer. Master of Science (Biochemistry and Molecular Biology), June 1998, 104 pp., 16 illustrations, bibliography, 94 titles. Insulin is an essential hormone and is produced exclusively in endocrine pancreas β-cells for the control of glucose homeostasis in mammals. The hypothesis tested in this thesis is that increased intracellular Ca2+ ([Ca2+]i) contributes to activation of glucose-induced insulin gene transcription. Glucose-induced insulin transcription has been mapped to binding of transcription factors by β-cell sequence motifs from -197 to -247, a glucose-response-enchancer (GRE), in the rat insulin1 gene (rINS1) promoter. Using oligonucleotide probes representing this glucose-response-enhancer (GRE) in electrophorectic mobility shift assays (EMSA), we have examined the Ca2+-sensitivity of transcription factor binding to nuclear extracts from cultured rat insulinoma β-cells (INS-1). In the presence or absence of kinase inhibitors, Ca2+ chelators, and Ca2+ channel blockers, binding was assayed for the following cell conditions: 1) in situ permeabilized cells exposed to Ca2+; 2) in vitro 32p-phosphorylated nuclear extracts; and 3) in situ glucose-stimulated and K+-depolarized intact cells. Binding was Ca2+-sensitive due to activation by K+depolarization as well as inhibition by a Ca2+-chelator, a Ca2+-channel blocker, and KN-93, specific for Ca2+/calmodulin kinases, suggesting a phosphorylation-dependent mechanism. Taken together, these findings identify a role for the Ca2+ second messenger in the glucose regulation of the insulin gene which points to novel treatments for type II diabetes.Item The Role of Calcium in Light-Induced Photoreceptor Apoptosis(2002-05-01) Krueger, Darrel Scott; Collier, Robert; Agarwal, Neeraj; Wordinger, Robert J.Krueger, Darrel Scott, The Role of Calcium in Light-Induced Photoreceptor Cell Apoptosis. Doctor of Philosophy (Biomedical Sciences), May, 2002; 305 pp., 15 tables, 31 illustrations, bibliography, 421 titles. Retinal degenerative diseases such as retinitis pigmentosa (RP) and age-related macular degeneration (AMD) result in loss of photoreceptors by apoptosis. Photo-oxidative stress accelerates the rate of photoreceptor apoptosis in models of retinal dystrophies. Thus, a better understanding of light-induced apoptosis is important for developing preventative and treatment options for persons with these blinding diseases. The goals of this dissertation were to investigate the effect of photo-oxidative stress on [Ca2+]I in rat photoreceptor cells and determine whether cell death could be prevented by altering cells’ abilities to manage [Ca2+]i. Thirty minutes of light exposure resulted in significant elevation of [Ca2+]i, determined using Fura-2 ratiometric imaging, which increased with additional light exposure. At 120 minutes, the F340/380 ratio was 3-times the beginning baseline ratio. Using multiple techniques indicative of early and late phases of apoptosis, changes consistent with apoptosis were observed, including early labeling (30 Min) with Annexin-V, activation of caspase-3 (2IIr), TUNEL labeling and Propidium Iodidc staining. TUNEL and Propidium labeling were more intense at 3Hrs light exposure, reflecting late phase changes. Apoptosis was confirmed using electron microscopy (TEM). TEM showed mitochondrial swelling, indicative of permeabilization, prior to chromatin condensation. Pharmacological agents were utilized to mediate participation of cellular calcium sources or storage sites in the maintenance of intracellular calcium homeostasis during photo-oxidative stress. Agents were separately added to the media prior to light exposure and their effects on cell viability were assessed using the Formazan assay. Mitochondria were confirmed to be the site of action affected by elevated [Ca2+]I, since prevention of calcium uptake by ruthenium red (1-100-μM) provided significant protection of cell viability in a dose-related manner. The 100- μM concentration resulted in complete maintenance of viability. BAPTA-AM also demonstrated some protection (50%) indicating that reduction of [Ca2+]I independent of source is beneficial is maintaining cell viability. Identification of mitochondrial uptake and cytosolic buffering of calcium as key viability determinants in light-induced apoptosis is a significant discovery for targeting future research for preventing or inhibiting photoreceptor cell apoptosis associated with retinal dystrophies such as RP and AMD.