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Articles 391 - 406 of 406

Full-Text Articles in Chemicals and Drugs

Molecular Composition Of The Louse Sheath, Craig N. Burkhart, B Artur Stankiewicz, Irene Pchalek, Michael A. Kruge, Craig G. Burkhart Jan 1999

Molecular Composition Of The Louse Sheath, Craig N. Burkhart, B Artur Stankiewicz, Irene Pchalek, Michael A. Kruge, Craig G. Burkhart

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Flash pyrolysis-gas chromatography/mass spectrometry was used to assess the chemical composition of the head louse's nit sheath. The pyrolyzate of the female insect's secretions, which form a cement-like cylinder holding the egg onto the hair, is dominated by amino acid derivatives and fatty acids. No chitin-specific compounds were detected in the sheath. These results, contrary to previous reports, show that the polymeric complex of the sheath is composed of proteinaceous moieties, possibly cross-linked to aliphatic components. This study constitutes the first chemical characterization of the pyrolysis products of insect (louse) glue and unequivocally confirms that louse sheaths are not chitinous, …


Affinity Chromatography: A Review Of Clinical Applications, David S. Hage Jan 1999

Affinity Chromatography: A Review Of Clinical Applications, David S. Hage

David Hage Publications

Affinity chromatography is a type of liquid chromatography that makes use of biological-like interactions for the separation and specific analysis of sample components. This review describes the basic principles of affinity chromatography and examines its use in the testing of clinical samples, with an emphasis on HPLCbased methods. Some traditional applications of this approach include the use of boronate, lectin, protein A or protein G, and immunoaffinity supports for the direct quantification of solutes. Newer techniques that use antibody-based columns for on- or off-line sample extraction are examined in detail, as are methods that use affinity chromatography in combination with …


Localization Of Sodium, Potassium-Adenosine Triphosphatase In The Cerebral Cortex Of Developing Rats, Maki Ujiie Sep 1998

Localization Of Sodium, Potassium-Adenosine Triphosphatase In The Cerebral Cortex Of Developing Rats, Maki Ujiie

Loma Linda University Electronic Theses, Dissertations & Projects

Active transport via Na+, K+-ATPase plays an important role in establishing and maintaining proper ionic gradient across all mammalian cell membranes. A strict regulation of Na+, and K+ ion levels is especially important in excitable cells such as neurons and myocytes. Inhibition of the enzyme is associated with several pathological conditions and has serious detrimental effects on cerebral cortical cells. Yet the enzyme appears to be limited in amount and distribution in newborn rats. In this study, Na+, K+- ATPase expression and distribution in early postnatal rats were studied …


Determination Of The N-Terminal Amino Acid Residues On Polypeptides In Secondary Wastewaters, Edward L. Creecy Jul 1998

Determination Of The N-Terminal Amino Acid Residues On Polypeptides In Secondary Wastewaters, Edward L. Creecy

Chemistry & Biochemistry Theses & Dissertations

The N-terminal amino acid residues on polypeptides and proteins were determined in wastewaters prior to chlorination. The terminal amino groups'ere first derivatized with the well known derivatizing agent dansyl chloride, and then the resulting dansyl amino acid hydrolyzed from the peptide chain by a propionic acid/ hydrochloric acid mixture. The resulting dansyl amino acids were then separated and detected using reversed phase high performance liquid chromatography with fluorescence detection. The majority of N-terminal residues detected were the more polar amino acids. Concentrations ranged from 1 x 10-10 to 3 x 10-7 moles/liter. It is suggested that the shorter …


Bulletin 4307 - Grass Control In Pastures Using Herbicides, Alexandra Wallace Oct 1995

Bulletin 4307 - Grass Control In Pastures Using Herbicides, Alexandra Wallace

Bulletins 4000 -

This Bulletin discusses three methods for herbicide control of grasses in pastures:

  • pasture manipulation, in the early stages of pasture growth;
  • spray-topping late in the growing season; and
  • hay freezing, late in the growing season.


Sds Non-Acrylamide Polymeric Gel-Filled Capillary Electrophoresis For Molecular Size Separation Of Protein, Devon Andres Aug 1993

Sds Non-Acrylamide Polymeric Gel-Filled Capillary Electrophoresis For Molecular Size Separation Of Protein, Devon Andres

Honors Theses

Sodium dodecyl sulfide (SDS) non-acrylamide gel-filled capillary columns are a new technology being used for analysis and separation of biotechnology-derived proteins. This research was to compare this new technology to the current methods of SDS polyacrylamide gel electrophoresis (SDS-PAGE) and high-performance size-exclusion chromatography (HPSEC). The molecular mass of four different recombinant proteins were determined by two commercialized SDS non-acrylamide gel-filled capillary columns, SDS-PAGE, and HPSEC. The data obtained showed that the SDS non-acrylamide gel-filled capillary columns were compatible with the SDS-PAGE technique for molecular mass determination. HPSEC was shown to be unreliable for molecular weight determination. SDS non-acrylamide gel-filled capillary …


The Isolation And Identification Of Polyphenolics From Grape Seeds And Their Activity Towards Specific Cell Lines, Joseph A. Reddy Jul 1993

The Isolation And Identification Of Polyphenolics From Grape Seeds And Their Activity Towards Specific Cell Lines, Joseph A. Reddy

Chemistry & Biochemistry Theses & Dissertations

Grape seed extract is being marketed in France for cardiovascular use and skin care. The active constituents of both these drugs are certain polyphenols called procyanidins. A similar seed extract has now been obtained from Virginia Chardonnay grape seeds. Ten of the major components in this extract have been isolated in their pure form by the semi-preparative HPLC separation on a YMC ODS-AQ (Octadecylsilane-AQ) column. The ODS-Aq column has been shown to have a better resolving capacity compared to the Spherisorb ODS (Octadecylsilane) column previously described in the literature. This has been attributed to the ODSAQ support which has both …


Improved Recovery Of A Radlolabeled Peptide With An Albumin-Treated Reversed-Phase Hplc Column, David S. Hage, Robert L. Taylor, Pai C. Kao Jan 1992

Improved Recovery Of A Radlolabeled Peptide With An Albumin-Treated Reversed-Phase Hplc Column, David S. Hage, Robert L. Taylor, Pai C. Kao

David Hage Publications

Reversed-phase high-performance liquid chromatography (RP-HPLC) is an important tool in the purification of radiolabeled peptides and proteins for immunoassay. However, for some proteins and peptides it is difficult to achieve reproducible behavior in RP-HPLC because of the low recovery of these compounds. Factors that can be varied to improve recovery include the strength or pH of the mobile phase, the chain length and spacing of groups on the reversed-phase support, and the flow rate or steepness of the elution gradient (1-5). ... In summary, we obtained better recovery and more reproducible chromatographic behavior for labeled 1-34 PTHrP with an albumin-pretreated …


Intact Parathyroid Hormone: Performance And Clinical Utility Of An Automated Assay Based On High-Performance Immunoaffinity Chromatography And Chemiluminescence Detection, David S. Hage, Bob Taylor, Pai C. Kao Jan 1992

Intact Parathyroid Hormone: Performance And Clinical Utility Of An Automated Assay Based On High-Performance Immunoaffinity Chromatography And Chemiluminescence Detection, David S. Hage, Bob Taylor, Pai C. Kao

David Hage Publications

The performance and clinical utility of an automated assay of intact parathyroid hormone (parathyrin, PTH) are evaluated. The method is based on the extraction of PTH from plasma by an HPLC column containing immobilized anti-(44-68 PTH) antibodies. The PTH retained is detected with a postcolumn reactor and use of anti-(1--34 PTH) chemiluminescent-labeled antibodies. The total cycle time of the assay is 6.5 mm per injection after a 1-h incubation.The lower limit of detection for PTH in a 66-pL plasma sample was 0.5 pmol/L based on peak heights and 0.2 pmol/L based on peak areas. Mean analytical recovery for PTH added …


Investigation Of Complex Formation By Oligomers Of Cytosine And Guanosine, Steven Roberts Davis Oct 1987

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 Tm 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 …


Fluoride As A Therapeutic Drug In Osteoporosis Treatment, Rita Priyadarshani Francis Jun 1987

Fluoride As A Therapeutic Drug In Osteoporosis Treatment, Rita Priyadarshani Francis

Honors Theses

The use of fluoride as a therapeutic drug is not a novel idea. Studies dealing with the effects of fluoride on the skeletal system date back to the late 1960's. This paper will define osteoporosis, examine methods of detection, and will discuss various methods of treatment with emphasis on the use of fluoride supplements in the form of tablets or fluorinated drinking water.


The Synthesis And Evaluation Of The Cardiovascular Activity Of Novel Imidazole Ring Systems, Joseph E. De Los Angeles Oct 1986

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 …


The Survival Of Mesophilic And Thermophilic Bacteria Subjected To Uv Irradiation, Sajida A. Shaikh Aug 1985

The Survival Of Mesophilic And Thermophilic Bacteria Subjected To Uv Irradiation, Sajida A. Shaikh

Masters Theses

Survival curves were determined for the mesophile, Bacillus licheniformis and the thermophile, Bacillus stearothermophilus after subjecting the cells to ultraviolet irradiation. Cells were grown at 37°C for the mesophile and at 55°C for the thermophile.

At low UV exposure times, the thermophile was more resistant to UV irradiation (had a better survival rate) than was the case for the mesophile. At higher exposure times, the situation was reversed, the mesophile having a greater survival rate than the thermophile.

The effect of changes in the temperature during irradiation was also determined. Thermophiles were greatly affected by changes in temperature while the …


Development Of An On-Line Computer System For Enzyme Kinetics Studies, Jacqueline R. Thweatt Jul 1982

Development Of An On-Line Computer System For Enzyme Kinetics Studies, Jacqueline R. Thweatt

Chemistry & Biochemistry Theses & Dissertations

The PDP-11/10 minicomputer was interfaced to the Beckman 25 ultraviolet/visible spectrophotometer and this on-line computer system was applied to enzyme kinetics studies. This interface involved hardware equipment to locate, amplify, and transmit the analog signal to an analog-to-digital converter, and software to acquire and store the digital data. Data processing programs were used to calculate kinetic parameters and statistical information from the acquired data.

The Varian Cary 219 ultraviolet/visible spectrophotometer can be readily interfaced to the Apple II Plus microcomputer by hardware equipment which can be purchased from the manufacturer. Various software may also be purchased for use in enzyme …


The Use Of Pickled Wheat In Poultry Feeding, P Smetana Jan 1969

The Use Of Pickled Wheat In Poultry Feeding, P Smetana

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

FEEDING fungicides to poultry can result in harmful effects, to the birds themselves, and to their human consumers.

To prevent such effects it is advisable that wheat pickled with fungicides should not be included in poultry rations.


The Preparation Of Coordination Compounds Of Rhodium (Iii) And Glutamic Acid And Substituted Glutamic Acids, Herman William Kalberer Jan 1969

The Preparation Of Coordination Compounds Of Rhodium (Iii) And Glutamic Acid And Substituted Glutamic Acids, Herman William Kalberer

University of the Pacific Theses and Dissertations

The father of coordination chemistry was Alfred Werner (1866- 1919). Werner's theory was largely responsible for the renewed interest in, and rapid growth of, inorganic chemistry around the turn of the century. He postulated that there were two types of valence, primary and secondary, which correspond, in modern terminology, to oxidation state and coordination number. The primary valences must be either negative ions, neutral molecules or, occasionally even, positive ions (11). He also postulated that the secondary valences are directed in space about the central ion, not only in the solid state, but also when the complex is in solution. …