Biochemistry Commons^™

The Determination Of Tamoxifen Citrate In Human Blood Serum And Semen, Karimdad Tahmoresi

Chemistry & Biochemistry Theses & Dissertations

High performance liquid chromatography (HPLC)methodologies for the determination of tamoxifen and its metabolites 4-hydroxytamoxifen and n-desmethyltamoxifen, and using cis-tamoxifen as an internal standard have been developed.

Clinical analyses of tamoxifen and its metabolites in human serum and semen, were performed as follows: The analytes were extracted from serum and semen with hexane, the hexane evaporated, the dried extract then reconstituted with methanol, followed by reverse phase high performance liquid chromatography.

Between-run coefficients of variation (CV'S) for tamoxifen and n-desmethyltamoxifen for serum sample analyses, (n = 15) were, 4% and 13% at mean (SD) concentration of 140.2 (6.2) and 71.8 (9.8) …

Regulation Of Queuine Insertion Into Transfer Rna: Effects Of Tumor Promoters, Bonnie Jean Brooks

Chemistry & Biochemistry Theses & Dissertations

The purpose of this study was to treat normal human fibroblasts with known tumor promoters and observe queuine modification of tRNA. The queuine insertion enzyme, tRNAguanine ribosyltransferase, was studied in vivo and in vitro. Tumor promoter-treated human fibroblast cultures exhibited variable queuine-insertion rates with a transient inhibition that correlated with variable levels of queuine modified tRNA over time in culture from passages 3 — 8. In contrast the in vitro studies showed that phorbol cetera and saccharin actually increased insertion with strong evidence indicating phosphorylation as a positive modulating force of the enzyme activity. It is proposed that chronic stimulation …

Microwell Based Competitive Enzyme Immunoassay For Quantifying Serum Triiodothyronine And Thyroxine Levels, Yiwen Yang

Chemistry & Biochemistry Theses & Dissertations

A microwell based competitive enzyme immunoassay for determination of total thyroxine and triiodothyronine in human serum was developed with use of horseradish peroxidase conjugate. The assay, which can be performed in only 1.5 hours at room temperature, involves simultaneous incubation of T₃- or T₄- HRPO conjugate and serum sample in anti-T₃ or anti-T₄ gamma globulin fraction coated polystyrene microwells.

Isolation of anti-T₃ and anti-T₄ gamma globulin fractions were accomplished from whole antiserum by using DEAE-cellulose chromatograph. A carbodiimide coupling method was described to prepare the T₄- and T₃-HRPO …

Regulation Of Epidermal Growth Factor Receptor Synthesis By Retinoic Acid And Dexamethasone, Kerby C. Oberg

Loma Linda University Electronic Theses, Dissertations & Projects

Fetal rat lung (FRL) cells incubated in the presence of retinoic acid or dexamethasone exhibit altered ¹²⁵I-epidermal growth factor (EOF) binding capacity. Retinoic acid enhances ¹²⁵I-EGF binding 3-fold following 24 hours of 37° incubation. In contrast, FRL cells incubated in the presence of dexamethasone display a 2-fold reduction in ¹²⁵I-EGF binding capacity. The change in binding capacity, induced by either hormone, was due to alterations in the average number of receptors per cell as determined by Scatchard analysis of ¹²⁵I-EGF binding. In the absence of retinoic acid or dexamethasone, FRL cells were calculated to have approximately …

Hypoxanthine-Induced Differentiation Of Cultured Human Leukemia Cells, Gayle Jennette Singleton

Chemistry & Biochemistry Theses & Dissertations

Human cultured leukemia cells appear to have a decreased amount of inosine in their tRNA. When cells with inosine deficient tRNA are placed in a hypoxanthine fortified media, they incorporate hypoxanthine into their tRNA by the action of the enzyme tRNA-hypoxanthine ribosyl transferase. This generates the nucleoside inosine in the tRNA. The cultured human leukemia cell lines, CCRF-CEM, HL-60, and HGPRT(-) HL- 60, incorporate hypoxanthine into their tRNA, as determined by tRNA isolation, hydrolysis, and HPLC analysis. Hypoxanthine treatment dramatically inhibited cell growth in conjunction with partial induction of differentiation in the CCRF-CEM, HL-60, and HGPRT ( - ) HL-60 …

Dietary And Hormonal Evaluation Of Men At Risk For Prostate Cancer, Donald J. Pusateri

Loma Linda University Electronic Theses, Dissertations & Projects

Relationships between dietary nutrients and plasma and fecal estrone, estradiol-17β, testosterone, and plasma prolactin levels were studied in young Seventh-day Adventist men: 18 nonvegetarians (NV), 20 lacto-ovovegetarians (LOV), and 15 vegans (V). Blood samples and 3 d dietary records were obtained. Contemporaneously collected diet composites and stool samples were analyzed for fiber. The vegetarians consumed significantly more fiber than the omnivores, while NVs and LOVs consumed more saturated fat than the Vs. Although plasma steroid hormone status did not differ, the Vs had significantly higher fecal estrogen levels than the NVs or LOVs. Plasma prolactin levels were significantly higher in …

The Synthesis And Evaluation Of 5-Phenyloxazolidines As Potential Cardiovascular Drugs, Tammy C. Wang

Chemistry & Biochemistry Theses & Dissertations

Drugs such as adrenoceptor antagonists and certain centrally acting agents are known to lower blood pressure and thus serve as clinically useful antihypertensive agents. Norepinephrine 4, a natural ∝-adrenoceptor agonist, is the major agent associated with increased blood pressure in the periphery. Based on a careful structure-activity comparison, a series of substituted oxazolidines, 20, 21, 22 and 23, have been designed as possible antihypertensive candidates. Specifically, 22 and 23 have been synthesized to serve as potential norepinephrine antagonists.

Preliminary evaluation of these compounds indicated that they were not antihypertensive in nature. The more active compound, 23, …

A Method For The Large Scale Purification Of Hcg (Human Chorionic Gonadotropin) From The Urine Of Pregnant Women, Chun-Shyan Kuo

Chemistry & Biochemistry Theses & Dissertations

A large scale preparation of human chorionic gonadotropin (HCG) from the urine of pregnant women was accomplished by using kaolin adsorption, NH₄OH extraction and DEAE-cellulose ion exchange. A recovery about 81% of HCG and a specific activity in the 2,000-3,000 IU/mg range was achieved using this purification method.

Two HCG activity fractions, HCG I & HCG II, were isolated from DEAE-cellulose chromatography by a stepwise sodium chloride gradient elution. HCG I was eluted at 0.01-0.02 M NaCl while HCG II was eluted at 0.12-0.02 M NaCl.

The differences between HCG I and HCG II have been studied. The …

An Analysis Of Protein-Ligand Interactions For Enzyme Ii-Mannitol From Escherichia Coli, Brent Lee Wood

Loma Linda University Electronic Theses, Dissertations & Projects

Enzyme II^mtl of Escherichia coli was purified from mtlA-overexpressing E. coli strain LJ1112 extraction of isolated membranes with deoxycholate, followed by hexyl agarose and ω-amino hexyl agarose chromatography in Lubrol PX. A 10-fold increase in total pure protein and 2.5-fold increase in specific activity over previously reported procedures was obtained. Tryptic fragments of Enzyme II^mtl were also purified and identified as the membrane and cytoplasmic domains by protein sequencing and SDS-PAGE. The fluorescence spectrum of Enzyme II^mtl suggested that two populations of tryptophan residues existed with emission maxima at 322 and 344 nm, corresponding to buried …

The Inhibition Of Bone Formation Occurring Under Weightlessness : The Effect Of Skeletal Unloading On Serum Levels Of A Bone-Derived Growth Factor, Jean D. Sibonga

Loma Linda University Electronic Theses, Dissertations & Projects

A deleterious effect of spaceflight on human health is the loss of bone associated with the prolonged lack of gravitational stress on the skeleton. A potential for bone loss is indicated by the hypercalciuria and decreased heel bone density determined in Skylab astronauts. Histological studies of juvenile laboratory rats in actual spaceflight and in simulation models document a suppression of bone formation with little alteration of bone resorption. The mechanism for net bone loss needs to be defined in order to develop measures for its prevention or correction.

Skeletal growth factors, which may mediate coupling and locally regulate bone volume …

Decreased Triiodothyronine Binding To The Hepatic Nuclear Thyroid Hormone Receptor In The Diabetic Mouse, Thomas J. Dewind

Loma Linda University Electronic Theses, Dissertations & Projects

The diabetic C57BL/KsJ-db m mouse has abnormal thyroid hormone levels and indications of thyroid hormone resistance. To investigate the basis of these abnormalities, the hepatic nuclear thyroid hormone receptor was extracted with 0.4 M KCl, 1.1 mM MgCl₂, 20 mM Tris/HCl, pH 7.9 from hepatocyte nuclei of normal C57BL/KsJ, heterozygous C57BL/KsJ-db m (db/m), and diabetic C57BL/KsJ-db m (db/db) mice. Normal and heterozygous mice were grouped together as the controls. Triiodothyronine (T₃) binding studies at 4°C using nitrocellulose filtration to separate free T₃ from receptor bound T₃ demonstrated an …

Time Delayed Protein Complementation, Diana L. Lakusta

Loma Linda University Electronic Theses, Dissertations & Projects

The time delayed complementation of plant proteins was tested in weanling Sprague-Dawley male rats by measuring growth rates as well as plasma and tissue free amino acids. Diets of pinto beans with rice, corn or wheat were pair-fed in combination or alternating 4 times a day at 6 and 11 am, and 4 and 9 pm for 4 weeks. Plasma, liver and muscle samples were obtained 2 hours postprandial, a time determined most suitable for sacrifice, and analyzed for free amino acids via ion-exchange chromatography. There were no significant differences in growth of rats fed combination or alternating diets.during week …

Synthesis And Characterization Of N-Alkyl-Adenosine-5'-Diphosphates, Han-Ping Huang

Chemistry & Biochemistry Theses & Dissertations

n-Alkylphosphates and adenosine derivatives have been observed to be competitive inhibitors of coenzyme molecules in many NAD⁺ requiring enzymes. In earlier studies, adenosine derivatives such as AMP, ADP and ADP-ribose were found to be coenzyme competitive inhibitors of the Lactate Dehydrogenase catalyzed reaction. However, n-alkylphosphates, to the contrary, + were found to be noncompetitive inhibitors of NAD⁺.

Furthermore, it was observed previously in Dr. Yuan's laboratory that the effect of n-octylphosphate on the LDH catalyzed reaction was changed from noncompetitive to competitive in the presence of low concentration of AMP. Rossmann et al. reported that the binding …

Investigation Of Complex Formation By Oligomers Of Cytosine And Guanosine, Steven Roberts Davis

Chemistry & Biochemistry Theses & Dissertations

Duplex formation between oligo(C:G) _n where n=3 to 4 was shown not to occur under conditions favorable for duplex formation between poly G and poly C. Instead, a stable guano sine self-structure was found to form which a T_m of 50°C for (Gp)₃ and 80°C for (Gp)₄ at strand concentrations of 10^-5M in 1M NaCl. Neither a duplex nor a self-structure formed in the absence of salt.

Oligomers of guanosine and cytosine were obtained by basic hydrolysis and separated according to chain length using DEAE Sephadex column chromatography. Separation of cytosine oligomers with chain lengths …

Biochemical And Histological Evaluation Of Normal Human Epidermis Vs Cultured Human Epidermis, Ngo Thi Bich Lien

Biological Sciences Theses & Dissertations

Cultured human keratinocytes were grown in vitro for transplantation purposes in case of severe burns. Single keratinocytes were harvested from human epidermis and grown in culture flasks such that multilayered sheets of keratinocyte cells were harvestable in approximately three weeks. In order to evaluate cultured epidermis for equivalency with normal human epidermis, biochemical and histological studies were performed. Thin sections of cultured epidermis were shown to be composed of cells that had undergone developmental differentiation, but not terminal differentiation. Biochemical analyses of keratin and prekeratin proteins isolated from cultured epidermis indicated that cultured keratinocytes have electrophoretic patterns similar to keratins/prekeratins …

The Synthesis And Evaluation Of The Cardiovascular Activity Of Novel Imidazole Ring Systems, Joseph E. De Los Angeles

Chemistry & Biochemistry Theses & Dissertations

An investigation was undertaken to synthesize and evaluate the cardiovascular activity of two imidazole ring systems. Imidazoles with hypotensive activity would provide novel potential antihypertensive drugs. These novel structures may also find use as chemical probes in the study of the cardiovascular system and as prototypes for other potential cardiovascular agents.

The histamine derivative, 7,7-dipyridyl-4,5,6,7-tetrahydroimidazo-[4,5-c]pyridine (ligand l), was demonstrated to possess significant hypotensive activity in laboratory rats. A 15 mg/Kg dose of ligand 1 produces a statistically significant decrease in blood pressure when injected IP. This hypotensive effect is also associated with marked increase in heart rate. Although compound 1 …

Determination Of Human Sperm Cell Acrosin Activity From Normal And Subfertile Men, Dilrowshan H. Haque

Chemistry & Biochemistry Theses & Dissertations

Acrosin is an acrosomal enzyme which is reported to be involved in sperm penetration through cumulus, zona, and ooplasma. This enzyme has been reported to be significantly lower in sperm of infertile men compared to sperm of fertile men. The acrosin assay which has been developed can be used for studies in patients with suspected infertility and may be used on a fraction of most semen specimens being evaluated in a clinical andrology laboratory.

Within-run precision studies yielded coefficients of variation of 11% for a low-activity pool and 9% for normalactivity pool specimens. Between-run precision studies using a single donor …

An Immunochemical Analysis Of Alcoholic Hyaline And Its Relationship To Keratin Intermediate Filaments, David L. Drexler

Loma Linda University Electronic Theses, Dissertations & Projects

Alcoholic Hyaline (AH) and keratin intermediate filaments possess ultrastructural, biochemical and immunochemical similarities. This study compares human AH, human stratum corneum keratin (HSCK) and normal human liver cytokeratin (HCK) by quantitative immunochemical means, using polyclonal as well as monoclonal antibodies. Enzyme-linked immunosorbent assays (ELISAs) were employed, as well as "immunoblotting" and immunocytochemical techniques. HCK was isolated using Triton X-100 and "high-salt” buffers and exhibited seven major polypeptide bands on SDS-PAGE (41-58 kd). Antisera were made toward HCK and the two major HCK bands. Other immunochemicals included antisera toward AH, the three major AH bands, and HSCK, as well as 3 …

Interaction Of Putative Estrogens And The Estrogen Receptor System In Leydig Cells In The Balb/C Mouse Testis Resulting In The Initiation Of Dna Synthesis, R. Lloyd Juriansz

Loma Linda University Electronic Theses, Dissertations & Projects

Continuous administration of estrogens for 7-9 months, both steroidal and nonsteroidal, to male BALB/c mice, leads to the formation of testicular Leydig cell tumors. Three days following the subcutaneous implantation of a pellet of estrogen in cholesterol, there is a peak in the incorporation of ³H-tymidine into the DNA of the interstitial cells. These effects are hypothesized to be mediated by the estrogen receptor system in the Leydig cell. Common experimental techniques for the measurement of hormone binding, such as dextran coated charcoal treatment, proved to be impossible to employ in this system, therefore a procedure was developed using …

The Effects Of Luteinizing Hormone And Adenosine 3',5'-Cyclic Monophosphate On Phospholipid Metabolism By Luteal Mitochondria, Jim John Sadighian

Chemistry & Biochemistry Theses & Dissertations

Luteinizing hormone (LH) increases intracellular concentrations of adenosine 3', 5 '-cyclic monophosphate and the phosphoinositides, phosphatidylinositol (PI), PI 4'-phosphate (PIP) and PI 4' .5 1 - bispbosphate (PIP₂). It is believed that cAMP and the phosphoinositides act concertedly to regulate mitochondrial conversion of cholesterol to pregnenolone. This study examined the effects of LH and N⁶ ,O² -dibutyryl cAMP (dbcAMP) on phospholipids metabolism by luteal mitochondria and the influence of dbcAMP and the phosphoinosi tides on mitochondrial steroid production. Mitochondria were isolated from unincubated and incubated luteal tissue by differential centrifugation. Phospholipids were extracted from the mitochondria …

Magnesium, Copper And Zinc Concentrations In Blood From Children With Diabetes Mellitus, Linda Lowers Jenkins

Chemistry & Biochemistry Theses & Dissertations

Trace element levels in blood from diabetic children were investigated and compared to control children. Plasma, erythrocyte, mononuclear and polymorphonuclear cells were analyzed for magnesium, copper, and zinc content. Leukocyte separation was performed by density gradient centrifugation on Ficoll-Hypaque, followed by washing steps to remove platelet contamination and hypotonic lysis to remove red cell contamination. Polarized Zeeman-effect atomic absorption spectroscopy was used for trace metal analysis.

Decreased plasma magnesium levels were observed in the diabetic children. This finding is well documented and probably due to increased urinary magnesium loss from glycosuria. Lymphocyte magnesium levels in the diabetic children were also …

Annual Ryegrass Toxicity Research Update, A G P Brown, P. Vogal

Journal of the Department of Agriculture, Western Australia, Series 4

Annual ryegrass toxicity (ARGT) is a complex disease that kills sheep and cattle grazing pastures which contain infected ryegrass. The disease results when a nematode (Anguina agrostis) and a batcerium (Corynebacterium sp.) invade annual ryegrass and cause the seed heads to become toxic as the grass dries off.

The bacterium produces a complex toxin of 18 glycolipid compounds or corynetoxins which have been found to be virtually identical to the antibiotic tunicamycin.

The Relationship Of Vitamins B-6 And B-12 To Plasma Homocysteine Levels In Men At Low- And High-Risk For Coronary Heart Disease, Marlene E. Swift

Loma Linda University Electronic Theses, Dissertations & Projects

There is evidence that homocysteine may be a factor in increasing the risk of coronary heart disease (CHD). To explore this relationship further, we assessed the interrelation of dietary vitamins B-6, B-12 and folate, and plasma pyridoxal-5'-phosphate and vitamin B-12 with plasma free and protein-bound homocysteine levels. Fasting blood and three-day dietary records were obtained from nine men low-risk (LR) and five at high-risk (HR) for CHD. The HR mean systolic blood pressure, total cholesterol (TC), and TC/cholesterol ratios were significantly higher than LR levels. Groups were comparable by age, weight, height, skinfolds, exercise, and smoking history. No significant difference …

Lectins, El-Nasir Lalani, M Wells

Department of Pathology and Laboratory Medicine

No abstract provided.

Methemoglobin Reduction In The Presence Of Various Concentrations Of Oxyhemoglobin, Ali Mansouri

Journal of the Arkansas Academy of Science

Methemoglobin reduction in human red blood cell is governed by many factors, one of which is the concentration of oxyhemoglobin. Experiments were conducted to determine the inhibition of methemoglobin reduction by oxyhemoglobin under concentrations approaching those in the red cell. Hemoglobin, methemoglobin reductase and cytochrome b₅ were prepared by routine protein purification methods. Methemoglobin reduction was carried out at 37° C in spectrophotometer. It is shown that methemoglobin concentration variation (at least when it is above 1 mM) does not change the reduction rate. Whereas, the ratio of methemoglobin to oxyhemoglobin determines the rate of methemoglobin reduction when all other …

Negative Cooperatively In The Binding Of 3-Aminopyridine Adenine Dinucleotide To L-Α-Glycero-3-Phosphate Dehydrogenase, David Wheeler

Chemistry & Biochemistry Theses & Dissertations

Glycerol-3-phosphate dehydrogenase catalyzes the reversible reaction:

NAD⁺ + G-3-P ⇌ NADH + DHAP + H⁺

The enzyme is found in organisms from E. coli to man. The primary function of the enzyme varies from organism to organism. Depending on the metabolism of the organism, the enzyme may function primarily to generate G-3-P for lipid (in organisms with a highly aerobic biosynthesis metabolism), or it may function primarily to produce NAD⁺ to support glycolysis. Complex multicellular organisms possess tissue specific isozymes of GPDH whose kinetic parameters reflect the relative importance of G-3-P and NAD⁺ production in various …

Extrathyroidal Human Biochemistry Of Monoiodotyrosine, Stanley Andrew Tan

Loma Linda University Electronic Theses, Dissertations & Projects

The existence of extrathyroidal monoiodotyrosine (MIT) has been debated because of uncertain results from measuring serum MIT. The reason is that the isotopic and chromatographic assays used have not been sensitive enough. This investigation undertook to establish the existence of MIT in serum utilizing a radioimmunoassay (RIA), to study the physiology of serum MIT, and to discover the pharmacologic effects of exogenous MIT.

MIT-binding antibody was raised in rabbits by immunization with an MIT-porcine thyroglobulin conjugate. The antiserum bound 40% of the labeled MIT at a final dilution of 1:1000. Incubation of 100 µ1 antiserum with 50 pg [^{125 …}

Two-Dimensional Electrophoretic Studies Of Normal Spematozoal Proteins, Ying Lin

Chemistry & Biochemistry Theses & Dissertations

Protein profiles of human spermatozoa have been mapped by using high resolution two-dimensional electrophoresis which combines isoelectric focusing as the first dimension and polyacrylamide gradient gels electrophoresis in SDS as the second dimension. The profiles of normal spermatozoa! extraction, acrosomal extraction and seminal plasma showed high resolution in its separation capability. No qualitative or quantitative differences were observed by using Coomassie Brilliant Blue R-250 staining in a much higher concentration of proteins. However, coomassie blue lacks the sensitivity to detect many minor components. Therefore, a silver staining procedure was used, which resulted in greatly increased sensitivity.

Samples from normal fertile …

The Effects Of Tri-O-Cresyl Phosphate On 2',3'-Cyclicnucleotide-3'-Phosphohydrolase Activity In Neural And Non-Neural Tissue Of The Rat, Mark K. Schlager

Chemistry & Biochemistry Theses & Dissertations

A total of 44 Long-Evans rats received 5.7 g/kg tri-O-cresyl phosphate (TOCP) orally every 3 days for 6 days. A second group of 13 rats received 4.6 g/kg orally every 3 days for 6 days. Animals were administered atropine sulfate (10 mg/kg) intraperitoneally every 6 hours or as needed to alleviate cholinergic symptoms. Ten control animals were given corn oil orally. Eight rats (18%) survived the 5.7 g/kg dose regimen and 5 rats (38%) survived the 4.6 g/kg dose regimen. Surviving rats were killed at 30-33 days post-dose. Signs of delayed neuropathy included ataxia and motor impairment.

The CNP activity …

Investigation Of The Coenzyme Binding Site Of Lactate Dehydrogenase From Chicken Muscle, Jia-Hwei Lin

Chemistry & Biochemistry Theses & Dissertations

Investigation of the coenzyme binding site of lactate dehydrogenase was approached by using coenzyme analogs. Inhibition studies of this enzyme using n-alkylphosphates as coenzyme analogs were performed with a fluorometric method. The results showed that all of the n-alkylphosphates were competitive inhibitors with respect to NAD⁺.

The n-alkyl-ADPs were synthesized from AMP and dicycloheaylammonium salts of n-alkylphosphates. The synthetic compounds were subjected to NMR spectroscopic studies, thin layer chromatography and determination of the ratio of adenosine moiety to phosphate groups. The results indicated that the synthetic compounds were n-alkyl-ADPs.

These synthetic compounds were used as coenzyme analogs in …