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Articles 13351 - 13380 of 13694

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

The Voluntary Water Quality Monitoring Program : 1982 Project Report, Barbara Welch, Judy Potvin, Mary Ellen Dennis Jan 1982

The Voluntary Water Quality Monitoring Program : 1982 Project Report, Barbara Welch, Judy Potvin, Mary Ellen Dennis

Maine Collection

The Voluntary Water Quality Monitoring Program : 1982 Project Report

by Barbara Welch, Judy Potvin & Mary Ellen Dennis

Division of Environmental Evaluation and Lake Studies, Maine Department of Environmental Protection, Augusta, Maine 1982.

Contents: Understanding Maine's Lakes and Ponds / Acknowledgement / Temperature / Dissolved Oxygen / Other Measures of Lake Water Quality / Nutrients / Algae and Chlorophyll a / Transparency / Morphometry / Sampling / Protection / Classification / Answers to Most Frequently Asked Questions / Glossary of Terms / Appendix A : Maximum, Minimum, and Mean Values / Appendix B : Phosphate Content of Common Cleansers …


Elastin Content Of The Aorta From The Quantitation Of The Desmosines, H. Patrick Covault Jan 1982

Elastin Content Of The Aorta From The Quantitation Of The Desmosines, H. Patrick Covault

Dissertations

No abstract provided.


The Uptake And Release Of Label From Endocytosed 35so4-Labeled Proteins In Cultured Mouse Peritoneal Macrophages, Susan Patterson Buktenica Jan 1982

The Uptake And Release Of Label From Endocytosed 35so4-Labeled Proteins In Cultured Mouse Peritoneal Macrophages, Susan Patterson Buktenica

Dissertations

No abstract provided.


The Effects Of Maternal Protein Deficiency On The Development Of Synaptic Plasma Membranes In Rat Offspring, Duane M. Smith Jan 1982

The Effects Of Maternal Protein Deficiency On The Development Of Synaptic Plasma Membranes In Rat Offspring, Duane M. Smith

Dissertations

No abstract provided.


Nuclear Envelope Proteins: Chemical Characteristics And Molecular Interactions Of The Lamins, David Lee Cochran Jan 1982

Nuclear Envelope Proteins: Chemical Characteristics And Molecular Interactions Of The Lamins, David Lee Cochran

Theses and Dissertations

The lamins are a group of proteins in a residual nuclear envelope fraction derived from the nuclear lamina. The absence of specific functional assays for the two predominant species, lamin A and lamin B, has complicated their biochemical characterization. Initial studies reported in this work involved the enzymic cleavage of isolated lamins A and B and another lamina protein with a molecular weight of 61,000-daltons. The results obtained with each of three enzymes indicated strong similarities between the three nuclear envelope proteins.

Further chemical characterization of the lamins has been achieved. Lamins A, B and C have been separated by …


Effects Of Pulsed Electric Fields On Mammalian Cell Membranes, Guy K. Smith Jan 1982

Effects Of Pulsed Electric Fields On Mammalian Cell Membranes, Guy K. Smith

Theses and Dissertations

The effect of pulsed electric fields on cell membranes were studied to investigate the effects of an electric field, per se, on biological systems, without the densometric and other technical problems associated with other forms of nonionizing radiation. Exposure of mouse splenocytes to a high voltage pulse resulted in an increase in membrane permeability to K+ that was dependent on both the electric field strength and the pulse duration. Exposure to a 2 μsec, 3.0 kV/cm pulse elicited a 50% loss of intracellular K+ indicating that the critical transmembrane potential (Vm) at breakdown was 1.26 volts …


Organic N-Chloramines: Chemistry And Toxicology, Frank E. Scully, Jr., Maxwell A. Bempong Jan 1982

Organic N-Chloramines: Chemistry And Toxicology, Frank E. Scully, Jr., Maxwell A. Bempong

Chemistry & Biochemistry Faculty Publications

The stability of aqueous solutions of organic N-chloramines, suspected of contaminating chlorinated water, has been studied. Two factors influence the decomposition of solutions of N-chloropiperidine and N-chlorodiethylamine: a spontaneous decomposition and photodecomposition. Since solutions of these compounds are relatively long-lived, a need for an analytical method for their identification is discussed. A new method is described which involves reaction of organic N-chloramines with arenesulfinic acid salts. The method gives high yields of stable arenesulfonamides. Several toxicological studies of N-chloropiperidine are described. The compound is mutagenic by Ames assay in Salmonella typhimurium strain TA 100 and does not require metabolic activation …


Iodothyronine 5'-Deiodinase: Solubilization, Partial Purification, And Characterization Of A Thyroxine Deiodinase Extracted From Rat Liver Membranes, Samuel C. Powell Jan 1982

Iodothyronine 5'-Deiodinase: Solubilization, Partial Purification, And Characterization Of A Thyroxine Deiodinase Extracted From Rat Liver Membranes, Samuel C. Powell

Dissertations

No abstract provided.


Electron Microscopic Demonstration Of Neural Connections Using Horseradish Peroxidase: A Comparison Of The Tetramethylbenzidine Procedure With Seven Other Histochemical Methods, Keith A. Carson, M-Marsel Mesulam Jan 1982

Electron Microscopic Demonstration Of Neural Connections Using Horseradish Peroxidase: A Comparison Of The Tetramethylbenzidine Procedure With Seven Other Histochemical Methods, Keith A. Carson, M-Marsel Mesulam

Biological Sciences Faculty Publications

Eight methods for the electron microscopic demonstration of horseradish peroxidase (HRP) labeling have been compared in adjacent series of vibratome sections of mouse lumbar spinal cord. The tracer, a HRP-wheat germ agglutinin (WGA) conjugate, was injected into the gastrocnemius muscle complex. Following retrograde axonal transport to the lumbar motor neurons and transganglionic anterograde transport of the tracer to the dorsal horn, the HRP activity was demonstrated in eight series of adjacent sections of lumbar spinal cord using eight methods. These included procedures using tetramethylbenzidine (TMB), benzidine dihydrochloride (BDHC), o-tolidine, paraphenylenediamine-pyrocatechol (PPD-PC), and 4 methods using 3,3'-diaminobenzidine (DAB). All eight methods …


A Microbial Reductive Conversion Of The Steffimycin Chromophore: Chemical And Mechanistic Studies On A Soluble, Nadhdependent, Nonflavin-Containing Reductase From Streptomyces Steffisburgensis, John Rollin Hofstetter Dec 1981

A Microbial Reductive Conversion Of The Steffimycin Chromophore: Chemical And Mechanistic Studies On A Soluble, Nadhdependent, Nonflavin-Containing Reductase From Streptomyces Steffisburgensis, John Rollin Hofstetter

Dissertations

An understanding of a microbial reduction of the anthracycline antibiotic, steffimycin (1) was approached from two directions. First, the NADH-dependent enzyme responsible for the reduction was purified from the Streptomyces steffisburgensis cytosol and characterized. Second, information was obtained on the reduction and oxidation of 1.

The enzyme was a single polypeptide chain, acidic, and stable in solution. It had a molecular weight of 80,000 and no prosthetic groups.

The 5-step purification process resulted in greater than 1,000-fold purification and a 9% yield of the homogenous enzyme from extracts of S. steffisburgensis cells.

The enzyme reduced 1 by a two-electron mechanism …


Correlation Between Glutathione Peroxidase Activity And Selenium Concentrations In Both Plasma And Erythrocytes, Agatha Dudzai Munyanyi Oct 1981

Correlation Between Glutathione Peroxidase Activity And Selenium Concentrations In Both Plasma And Erythrocytes, Agatha Dudzai Munyanyi

Chemistry & Biochemistry Theses & Dissertations

Plasma and erythrocyte glutathione peroxidase activities and selenium concentrations were determined for 38 apparently healthy female subjects. In addition, erythrocyte lead and plasma lead and iron concentrations were determined in each subject.

Effects of age, smoking, vitamin and mineral supplementation, use of caffeinated beverages and oral contraceptives on glutathione peroxidase activity were determined and interelement relationships were investigated using the one tailed t-test and Spearman Rank Correlation Coefficients


In Vitro Enzymatic Assay Of Rna Methylation, Pamela Jean Eubanks Gallup Jul 1981

In Vitro Enzymatic Assay Of Rna Methylation, Pamela Jean Eubanks Gallup

Chemistry & Biochemistry Theses & Dissertations

An assay procedure for in vitro enzymatic methylation of mannnalian ribosomal RNA has been developed in this study. The assay procedure, utilized for the comparison of normal and neoplastic methylase activities (using mouse liver and Ehrlich ascites cells as sources of enzyme), is a modification of previously published methods (52,53). A 100,000 x g supernatant (SlOO) enzyme preparation was incubated with 28S-5.8S rRNA and tritium-labeled S-adenosyl-L-methionine. The RNA was extracted, applied to DEAE cellulose paper, washed, and the radioactivity counted. The neoplastic cell methylase preparation was more active in methylating both exogenous neoplastic and normal 28S-5.8S rRNA than the normal …


The Mechanism Of Aerotaxis In Salmonella Typhimurium, Daniel John Laszlo Jun 1981

The Mechanism Of Aerotaxis In Salmonella Typhimurium, Daniel John Laszlo

Loma Linda University Electronic Theses, Dissertations & Projects

Chemotaxis is the migrational response of bacteria to chemical gradients. Aerotaxis, the response to oxygen, was among the earliest observed tactic phenomena, but progress in the study of aerotaxis was previously limited by the available assays. These assays relied upon oxygen depletion by the bacteria to generate the oxygen gradient which elicits the behavioral response. Such assays are unsuitable for analyzing the role of the electron transport system in aerotaxis. In this study the biochemical mechanism of aerotaxis and its relationship to other chemotaxis pathways in Salmonella typhimurium was explored with the aid of two new assays which imposed an …


Chemical And Biological Structure Of Lake Mead Sediments, Richard T. Prentki, Larry J. Paulson, John R. Baker Jun 1981

Chemical And Biological Structure Of Lake Mead Sediments, Richard T. Prentki, Larry J. Paulson, John R. Baker

Publications (WR)

Lake Mead has undergone a serious decline since Glen Canyon Dam was constructed 450 km upstream in 1963.

State fisheries management agencies are concerned that the decline was caused by water level fluctuations and more severe drawdowns during the bass spawning season, when the operation of Hoover Dam was altered during the post-Lake Powell period.

The construction of Glen Canyon Dam and formation of Lake Powell in 1963 drastically altered the natural discharge and temperature cycles and decreased suspended sediment and nutrient loading in the Colorado River inflow to Lake Mead. Recent studies indicate that these changes in nutrient loading …


The Transport And Intracellular Distribution Of Iron In The Basidiomycete, Ustilago Sphaerogena, Charles W. Passavant May 1981

The Transport And Intracellular Distribution Of Iron In The Basidiomycete, Ustilago Sphaerogena, Charles W. Passavant

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The transport and intracellular distribution of iron in Ustilago sphaerogena via the native siderochrome ferrichrome A has been examined. Evidence is presented which suggests the involvement of deferriferrichrome in iron transport when the metal is supplied to the cell as ferrichrome A. This process requires both oxygen and ATP synthesis and may require a transmembrane electrochemical gradient. Once inside the cell, iron derived from ferrichrome A is rapidly distributed, with a major fraction found in the mitochondria, presumably as heme.

The kinetics of ferrichrome and ferrichrome A uptake have also been investigated. The Km of transport of ferrichrome was …


An Enzyme-Linked Immunosorbent Assay (Elisa) For Pantothenate, Allen H. Smith May 1981

An Enzyme-Linked Immunosorbent Assay (Elisa) For Pantothenate, Allen H. Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An enzyme-linked immunosorbent assay (ELISA) for pantothenate has been developed. Antibodies induced in rabbits against bovine serum albumin-pantothenate conjugate were specifically purified by affinity chromatography. This process served to reduce the amount of endogenous pantothenate attached to the antibody, as well as to purify the antibody. The purified antibodies were covalently linked to alkaline phosphatase (Sigma type VII) with glutaraldehyde (0.05% aqueous solution). An immobilized pantothenate substrate was first obtained by attaching human serum albumin-pantothenate conjugate to the surface of polystyrene culture tubes by passive adsorption. The binding of the enzyme labelled antibody (E-AB) to this substrate is proportionately inhibited …


High Performance Liquid Chromatographic Analysis Of Biogenic Amines, Thais Edwina Ahrendt Keegan Apr 1981

High Performance Liquid Chromatographic Analysis Of Biogenic Amines, Thais Edwina Ahrendt Keegan

Chemistry & Biochemistry Theses & Dissertations

The objectives of this research were to develop a sensitive method for separation and quantitation of biogenic amines and to apply that procedure by monitoring neurochemical changes resulting from stimuli to the test system.

Primary aromatic amines were derivatized with o-phthalaldehyde-mercaptoethanol prior to chromatography, Separation of the fluorescent adduct was achieved using a μBondapak/ phenyl reversed-phase column and a two-step gradient of methanol:0.08 M acetic acid, pH J.O. Fluorescence was monitored using a J40 nm excitation energy and an emission filter which transmits radiation greater than 400 nm (50% T at 418 nanometers).

Following optimization of the chromatographic conditions, studies …


The Synthesis And Evaluation Of The Biological Activity Of Heterocyclic Analogs Of Phencyclidine, Julian Dew Mckenney Jr. Apr 1981

The Synthesis And Evaluation Of The Biological Activity Of Heterocyclic Analogs Of Phencyclidine, Julian Dew Mckenney Jr.

Chemistry & Biochemistry Theses & Dissertations

Using the classical synthetic approach described by Maddox and co-workers43, the decyanation reaction of 1- piperidinocyclohexane carbonitrile (PCC), 5, was attempted using the heterocyclic anions of 2-methyl-5-nitropyridine, 22, 2-amino-5-nitropyridine, 23, and 2-hydroxy-5-nitropyridine, 24; however, the desired pyridine analogs of phencyclidine (PCP), 1, could not be prepared under these conditions. Attempts to prepare the same analogs via addition of these anions to the iminium tosylate and hydrobromide salts also proved unsuccessful.

The failure to observe the desired decyanation reaction has been attributed to the special sterochemical restrictions of the hindered nitrile of PCC in that facile …


Food Habits Of Largemouth Bass, Micropterus Salmoides (Lacepede) And Spotted Bass, Micropterus Punctulatus (Rafinesque), From Beech Fork Reservoir, A New Impoundment In Wayne And Cabell Counties, West Virginia, Michael A. Arcuri Jan 1981

Food Habits Of Largemouth Bass, Micropterus Salmoides (Lacepede) And Spotted Bass, Micropterus Punctulatus (Rafinesque), From Beech Fork Reservoir, A New Impoundment In Wayne And Cabell Counties, West Virginia, Michael A. Arcuri

Theses, Dissertations and Capstones

A study was undertaken to determine the food habits of two game fishes, the largemouth bass Micropterus salmoides (Lacepede) and the spotted bass M. punctulatus (Rafinesque) in Beech Fork Reservoir shortly after its impoundment. A total of 171 largemouth bass and 95 spotted bass were collected from July 1978, through June 1979, and their stomach contents analyzed.

Largemouth bass fed primarily on fishes, particularly young-of-the-year bluegill. Aquatic and terrestrial invertebrates were also important food items, especially during the spring and fall . The dominant aquatic forms were chironomid larvae and pupae while the dominant terrestrial forms were adult dipterans.

Spotted …


Neurochemical Studies On The Metabolism And Effects Of Catecholic Isoquinolines, T. C. Origitano Jan 1981

Neurochemical Studies On The Metabolism And Effects Of Catecholic Isoquinolines, T. C. Origitano

Dissertations

No abstract provided.


Electron Spin Resonance Studies Of Membrane Fluidity Of Normal And Malignant Human Neural Tissues, Robert P. Wersto Jan 1981

Electron Spin Resonance Studies Of Membrane Fluidity Of Normal And Malignant Human Neural Tissues, Robert P. Wersto

Dissertations

No abstract provided.


Peptidohydrolases Of Soybean Root Nodules, Nasir S. A. Malik, N. E. Pfeiffer, D. R. Williams, Fred W. Wagner Jan 1981

Peptidohydrolases Of Soybean Root Nodules, Nasir S. A. Malik, N. E. Pfeiffer, D. R. Williams, Fred W. Wagner

Department of Biochemistry: Faculty Publications

Nodule extracts prepared from Glycine max var Woodworth possessed endopeptidase, aminoptidase, and carboxypeptidase actiities. Three distinct endopeptidase activities could be resolved by disc-gel electrophoresis at pH 8.8. According to their order of increasing electrophoretic mobility, the first of these enzymes hydrolyzed azocasein and n-benzoyl-LLeu-β-naphthylamide, while the second hydrolyzed n-benzoyl-L-Arg-/8- naphthylamine (Bz-L-Arg-/βNA), n-benzoyl-L-Arg-β-nitroanilide (Bz-L-Arg-βNA), and azocasein. The third endopeptidase hydrolyzed Bz-L-Arg-βNA, Bz-L-Arg-βNA, and hemoglobin. Fractions of these enzymes extracted from electrophoresis gels were shown to have pH optima from 7.5 to 9.8. AU of the endopeptidases were completely inhibited by diisopropylphosphorofluoridate, demonstrating that they were serine proteases.


Thermodynamics Of Association And Catalysis Of N-Acyl-Peptidyl-Phenylalanine Amide Substrates By Chymotrypsin, John Paul Huff Jan 1981

Thermodynamics Of Association And Catalysis Of N-Acyl-Peptidyl-Phenylalanine Amide Substrates By Chymotrypsin, John Paul Huff

Dissertations

No abstract provided.


The Role Of Suppressor T Lymphocytes In Renal Allograft Rejection, Fred Barry Pearlman Jan 1981

The Role Of Suppressor T Lymphocytes In Renal Allograft Rejection, Fred Barry Pearlman

Master's Theses

No abstract provided.


Effects Of Glucocorticoid Treatment On The Properties Of Single Notor Units In Cat Hindlinb Huscles, Andrew James Robinson Jan 1981

Effects Of Glucocorticoid Treatment On The Properties Of Single Notor Units In Cat Hindlinb Huscles, Andrew James Robinson

Theses and Dissertations

The administration of glucocorticoids has been shown to induce atrophy and weakness in whole skeletal muscle. These effects frequently appear to be more pronounced in pale muscle than in red muscle. The present study was undertaken to examine the effects of steroid treatment on the contractile, electrical, and fatigue properties of single meter units in pale and red cat hindlimb muscles. Single motor units in the medial gastrocnemius (MG) and soleus muscles were isolated using techniques developed by McPhedran, et al., (1965). The properties of a large number of motor units were examined in normal animals and were compared to …


Physical Properties Of Dna From Synchronously Grown Mesophilic And Thermophilic Bacteria, Carol A. Cox Dec 1980

Physical Properties Of Dna From Synchronously Grown Mesophilic And Thermophilic Bacteria, Carol A. Cox

Masters Theses

No abstract provided.


The Effect Of Lead On Developing Rat Brain Lipids, Larry J. Stegink Dec 1980

The Effect Of Lead On Developing Rat Brain Lipids, Larry J. Stegink

Masters Theses

The objective of this study was to determine the effect of lead on the brain lipids of developing rats.

Lead acetate was added to the drinking water of two pregnant rats. A' control dam was maintained on the same diet without the lead. Following birth and weaning the lead concentration was reduced and an equal number of pups from each litter were sacrificed on days 19, 22, 26, 30, and 35 after birth. The brain lipids were isolated and fatty acid distribution analyzed by gas-liquid chromatography.

Variations in fatty acid distribution between the control and experimental pups were noted for …


Methods For Biological, Chemical, And Physical Analyses In Reservoirs, Penelope E. Kellar, Sherell A. Paulson, Larry J. Paulson Dec 1980

Methods For Biological, Chemical, And Physical Analyses In Reservoirs, Penelope E. Kellar, Sherell A. Paulson, Larry J. Paulson

Publications (WR)

This manual contains detailed descriptions of biological, chemical and physical sampling and analytical procedures used at the Lake Mead Limnological Research Center. The manual was prepared in response to requests made by numerous individuals involved in the Las Vegas Valley Water Quality Program. This manual represents what we consider to be a reasonably complete compilation of methods useful in studying both general and specific limnological questions. While each section is sufficiently detailed to be of use to investigators with little experience in limnological methodology, the methods can be used on a wide variety of lakes and reservoirs, with relatively little …


The Synthesis And Biochemical Evaluation Of Potential Acetylcholinesterase Reactivators, Andrea Mcdearmid Lunsford Oct 1980

The Synthesis And Biochemical Evaluation Of Potential Acetylcholinesterase Reactivators, Andrea Mcdearmid Lunsford

Chemistry & Biochemistry Theses & Dissertations

Objectives of this research were to (1) synthesize, and (2) evaluate new compounds which would be potential reactivators of organophosphate-inhibited acetylcholinesterase.

A series of 1,8-diazafluorenone and 2,2'bipyridylketone oximes and oxime methiodides were synthesized (11, 13, 14, 22, 24). These compounds were developed as structural analogs of 2-PAM (2-Pyridinealdoxime methiodide) and TMB-4 (1,1Trimethylene-Bis(4-formylpyridinium bromide)dioxime), the current drugs of choice for treatment of organophosphorous poisoning.

Acetylcholinesterase from electric eel was inhibited with DFP (diisopropylfluorophosphate), an irreversible-type inhibitor, and the inhibited enzyme was treated with the various reactivator compounds. The reactivation assays were monitored with pH stat apparatus, and the data were evaluated …


Functions Of Deadenylation Factors In Mrna Decay And Mrna Processing Body Formation, Dinghai Zheng Sep 1980

Functions Of Deadenylation Factors In Mrna Decay And Mrna Processing Body Formation, Dinghai Zheng

Dissertations and Theses (Open Access)

Most newly synthesized messenger RNAs possess a 5’ cap and a 3’ poly(A) tail. The process of poly(A) tail shortening, also termed deadenylation, is important for post-transcriptional gene regulation, because deadenylation not only leads to mRNA translational inhibition but also is the first step of major mRNA degradation. Translationally inhibited mRNAs can be stored and/or degraded in dynamic cytoplasmic foci termed mRNA processing bodies, or P bodies, which are conserved in eukaryotes.

To shed new light on the mechanisms of P body formation and P body functions, I focused on the link between deadenylation factors and P bodies. I found …