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2001

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Articles 1 - 18 of 18

Full-Text Articles in Biochemistry

Molecular Mechanisms Involved In Human Platelet Aggregation By Synergistic Interaction Of Platelet-Activating Factor And 5-Hydroxytryptamine, B H. Shah, H Rasheed, I H. Rahman, A H. Shariff, F L. Khan, H B. Rahman, S Hanif, S A. Saeed Dec 2001

Molecular Mechanisms Involved In Human Platelet Aggregation By Synergistic Interaction Of Platelet-Activating Factor And 5-Hydroxytryptamine, B H. Shah, H Rasheed, I H. Rahman, A H. Shariff, F L. Khan, H B. Rahman, S Hanif, S A. Saeed

Department of Biological & Biomedical Sciences

Our recent studies have shown that co-activation of Gq and Gi proteins by 5-hydroxytryptamine (5-HT) and adrenaline show synergism in human platelet aggregation. This study was conducted to examine the mechanism(s) of synergistic interaction of 5-HT and platelet activating factor (PAF) in human platelets. We show that PAF, but not 5-HT, increased platelet aggregation in a concentration-dependent manner. However, low concentrations of 5-HT (2 microM) potentiated platelet aggregation induced by subthreshold concentration of PAF (40 nM) indicating a synergistic interaction between the two agonists and this synergism was blocked by receptor antagonists to either 5-HT or PAF. 5-HT also potentiated …

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Aerobic Biodegradation Of Methyl Tert-Butyl Ether By Aquifer Bacteria From Leaking Underground Storage Tank Sites, S. R. Kane, H. R. Beller, T. C. Legler, C. J. Koester, Holly C. Pinkart, R. U. Halden, A. M. Happel Dec 2001

Aerobic Biodegradation Of Methyl Tert-Butyl Ether By Aquifer Bacteria From Leaking Underground Storage Tank Sites, S. R. Kane, H. R. Beller, T. C. Legler, C. J. Koester, Holly C. Pinkart, R. U. Halden, A. M. Happel

All Faculty Scholarship for the College of the Sciences

The potential for aerobic methyl tert-butyl ether (MTBE) degradation was investigated with microcosms containing aquifer sediment and groundwater from four MTBE-contaminated sites characterized by oxygen-limited in situ conditions. MTBE depletion was observed for sediments from two sites (e.g., 4.5 mg/liter degraded in 15 days after a 4-day lag period), whereas no consumption of MTBE was observed for sediments from the other sites after 75 days. For sediments in which MTBE was consumed, 43 to 54% of added [U-14C]MTBE was mineralized to14CO2. Molecular phylogenetic analyses of these sediments indicated the enrichment of species closely …

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Problem-Based Learning Variant: Transition Phase For A Large Institution, I Khan, A Fareed Aug 2001

Problem-Based Learning Variant: Transition Phase For A Large Institution, I Khan, A Fareed

Department of Biological & Biomedical Sciences

Objective: To compare students' test scores and perceptions of problem-based learning (PBL) and lecture-based learning (LBL) by applying a PBL-variant.
Method: For the transition from LBL to PBL, PBL was varied for one discipline only and for a large group of students. Two hundred forty nine second year medical students were taught a topic of Biochemistry by the LBL method and then 141 of these were taught another topic by the PBL-variant. At the conclusion of each topic an MCQ test was given. One week later a 9 item questionnaire was given to the 50 students now attending classes to …

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Sir3-Dependent Assembly Of Supramolecular Chromatin Structures In Vitro, Philippe T. Georgel, Madeleine A. Palacios Debeer, Gregory Pietz, Catherine A. Fox, Jeffrey C. Hansen Jul 2001

Sir3-Dependent Assembly Of Supramolecular Chromatin Structures In Vitro, Philippe T. Georgel, Madeleine A. Palacios Debeer, Gregory Pietz, Catherine A. Fox, Jeffrey C. Hansen

Biological Sciences Faculty Research

Baculovirus-expressed recombinant Sir3p (rSir3p) has been purified to near homogeneity, and its binding to naked DNA, mononucleosomes, and nucleosomal arrays has been characterized in vitro. At stoichiometric levels rSir3p interacts with intact nucleosomal arrays, mononucleosomes, and naked DNA, as evidenced by formation of supershifted species on native agarose gels. Proteolytic removal of the core histone tail domains inhibits but does not completely abolish rSir3p binding to nucleosomal arrays. The linker DNA in the supershifted complexes remains freely accessible to restriction endonuclease digestion, suggesting that both the tail domains and nucleosomal DNA contribute to rSir3p–chromatin interactions. Together these data indicate …

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Intrasteric Inhibition Of Atp Binding Is Not Required To Prevent Unregulated Autophosphorylation Or Signaling By The Insulin Receptor, Mark Frankel, Ararat J. Ablooglu, Joseph W. Leone, Elena Rusinova, J. B. A. Ross, Robert L. Heinrikson, Ronald A. Kohanski Jul 2001

Intrasteric Inhibition Of Atp Binding Is Not Required To Prevent Unregulated Autophosphorylation Or Signaling By The Insulin Receptor, Mark Frankel, Ararat J. Ablooglu, Joseph W. Leone, Elena Rusinova, J. B. A. Ross, Robert L. Heinrikson, Ronald A. Kohanski

Chemistry and Biochemistry Faculty Publications

Receptor tyrosine kinases may use intrasteric inhibition to suppress autophosphorylation prior to growth factor stimulation. To test this hypothesis we made an Asp1161Ala mutant in the activation loop that relieved intrasteric inhibition of the unphosphorylated insulin receptor (IR) and its recombinant cytoplasmic kinase domain (IRKD) without affecting the activated state. Solution studies with the unphosphorylated mutant IRKD demonstrated conformational changes and greater catalytic efficiency from a 10-fold increase in kcat and a 15-fold-lower Km ATP although Km peptide was unchanged. Kinetic parameters of the autophosphorylated mutant and wild-type kinase domains were virtually identical. The Asp1161Ala mutation increased the …

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An Enzymatic Method For The Detection Of Human Serum Albumin, M U. Javed, S N. Waqar Jun 2001

An Enzymatic Method For The Detection Of Human Serum Albumin, M U. Javed, S N. Waqar

Department of Biological & Biomedical Sciences

Albumin is the most abundant protein in human serum. A dye-binding method is commonly used in clinical laboratories for its estimation using different types of dyes. However, all these dye methods were interfered by a variety of compounds. Here we present a method for the detection of albumin in human serum and other biological fluids. The principle is based on the fact that lactate dehydrogenase isoenzyme-5 (LDH-5) binds specifically to Dextran-Blue (DB). Albumin inhibits the binding of LDH-5 with DB. Absence of LDH activity in DB fraction after gel filtration indicates the presence of albumin in sample and vice versa.

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Complex Effects Arising In Smoke Plume Simulations Due To Inclusion Of Direct Emissions Of Oxygenated Organic Species From Biomass Combustion, Sherri A. Mason, Richard J. Field, Robert J. Yokelson, Michael A. Kochivar, Mark R. Tinsley, Darold E. Ward, Wei Min Hao Jun 2001

Complex Effects Arising In Smoke Plume Simulations Due To Inclusion Of Direct Emissions Of Oxygenated Organic Species From Biomass Combustion, Sherri A. Mason, Richard J. Field, Robert J. Yokelson, Michael A. Kochivar, Mark R. Tinsley, Darold E. Ward, Wei Min Hao

Chemistry and Biochemistry Faculty Publications

Oxygenated volatile organic species (oxygenates), including HCOOH, H2CO, CH3OH, HOCH2CHO (hydroxyacetaldehyde), CH3COOH, and C6H5OH, have recently been identified by Fourier transform infrared measurements as a significant component of the direct emissions from biomass combustion. These oxygenates have not generally been included in the hydrocarbon-based initial emission profiles used in previous photochemical simulations of biomass combustion smoke plumes. We explore the effects of oxygenates on this photochemistry by using an established initial emission hydrocarbon profile and comparing simulation results obtained both with and without addition of the above six …

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Induction Of White Cell Proliferation Due To Haematopoietic Growth Factors Is Associated With An Increase In Multiple Forms Of Dihydrofolate Reductase In Non-Neutropenic Cancer Patients, M P. Iqbal, I A. Burney, F Sultana, N Mehboobali Feb 2001

Induction Of White Cell Proliferation Due To Haematopoietic Growth Factors Is Associated With An Increase In Multiple Forms Of Dihydrofolate Reductase In Non-Neutropenic Cancer Patients, M P. Iqbal, I A. Burney, F Sultana, N Mehboobali

Department of Biological & Biomedical Sciences

Objective: Granulocyte-colony stimulating factor (G-CSF) and granulocyte macrophage-colony stimulating factor (GM-CSF) are frequently used in cancer patients to overcome the granulocytopenic effects of chemotherapy, and also to mobilize the stem cells. The mobilized stem cells are collected from the peripheral blood and used for transplantation following high doses of chemotherapy. However, the molecular mechanism by which these colony stimulating factors (CSFs) bring about proliferation of myeloid precursor cells is not clearly known. Dihydrofolate reductase (DHFR), which has an established role in DNA synthesis, could be a link between administration of CSF and stem cell proliferation. The purpose of this study …

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A Crystallographic Map Of The Transition From B-Dna To A-Dna, Jeff Vargason, Keith Henderson, P. Shing Ho Jan 2001

A Crystallographic Map Of The Transition From B-Dna To A-Dna, Jeff Vargason, Keith Henderson, P. Shing Ho

Faculty Publications - Department of Biological & Molecular Science

No abstract provided.

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Protein Targeting And Translocation, Barry D. Bruce, D.A. Phoenix Jan 2001

Protein Targeting And Translocation, Barry D. Bruce, D.A. Phoenix

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

No abstract provided.

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Identification Of The Domains Of Urer, An Arac-Like Transcriptional Regulator Of The Urease Gene Cluster In Proteus Mirabilis, Carrie A. Poore, Christopher Coker, Jonathan D. Dattelbaum, Harry L.T. Mobley Jan 2001

Identification Of The Domains Of Urer, An Arac-Like Transcriptional Regulator Of The Urease Gene Cluster In Proteus Mirabilis, Carrie A. Poore, Christopher Coker, Jonathan D. Dattelbaum, Harry L.T. Mobley

Chemistry Faculty Publications

Proteus mirabilis urease catalyzes the hydrolysis of urea to CO2 and NH3, resulting in urinary stone formation in individuals with complicated urinary tract infections. UreR, a member of the AraC family, activates transcription of the genes encoding urease enzyme subunits and accessory proteins, ureDABCEFG, as well as its own transcription in the presence of urea. Based on sequence homology with AraC, we hypothesized that UreR contains both a dimerization domain and a DNA-binding domain. A translational fusion of the leucine zipper dimerization domain (amino acids 302 to 350) of C/EBP and the C-terminal half of UreR …

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Nitric Oxide Mediated Effect Of Cyclo-Oxygenase Inhibitors, M Mahmood, H S. Zuberi, M K. Ashfaq Jan 2001

Nitric Oxide Mediated Effect Of Cyclo-Oxygenase Inhibitors, M Mahmood, H S. Zuberi, M K. Ashfaq

Department of Biological & Biomedical Sciences

Objectives: Non-Steroidal anti-inflammatory drugs (NSAIDS) have long been used as anti-inflammatory agents, yet their mode of action is not entirely clear. The inhibitory effects of NSAIDS on prostaglandin production can only partly explain their anti-inflammatory actions. This study was aimed at defining the role of cycl-oxygenase (COX) inhibitors on nitric oxide (NO) production in murine macrophages in vitro.
Methods: Murine macrophages were obtained from the peritoneum and after exposure, in vitro to lipopolysaccharide (LPS) produced nitrite, measured after 24 hours by Griess reaction. The macrophages were pre-incubated with aspirin or indomethacin before activation with LPS.
Results: Treatment with aspirin resulted …

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Antifungal Activity Of Substituted 8-Quinolinol-5- And 7-Sulfonic Acids: A Mechanism Of Action Is Suggested Based On Intramolecular Synergism / Hermon Gershon, Muriel Gershon, & Donald D. Clarke Harding Laboratory, The New York Botanical Garden, Bronx, New York 10458, Usa; Department Of Chemistry, Fordham University, Bronx, New York 10458, Usa, Herman Gershon, Muriel Gershon, Donald Dudley Clarke Phd Jan 2001

Antifungal Activity Of Substituted 8-Quinolinol-5- And 7-Sulfonic Acids: A Mechanism Of Action Is Suggested Based On Intramolecular Synergism / Hermon Gershon, Muriel Gershon, & Donald D. Clarke Harding Laboratory, The New York Botanical Garden, Bronx, New York 10458, Usa; Department Of Chemistry, Fordham University, Bronx, New York 10458, Usa, Herman Gershon, Muriel Gershon, Donald Dudley Clarke Phd

Chemistry Faculty Publications

8-Quinolinol-5-sulfonic acid was nearly devoid of antimicrobial activity, due to what was believed to be an unfavorable partition coefficient. Since twenty six 8-quinolinol-5- and 7 -sulfonic acids were available from our previous work, they were tested against six fungi. The 7 -chloro and 7 -bromo-5-sulfonic acids and the 5-chloro and 5-bromo-7 -sulfonic acids showed fungal inhibition within one order of magnitude of that of 8-quinolinol. It is suggested that a nonchelating mechanism is in part responsible for this fungitoxicity. Five additional 5-sulfonic acids with chlorine in positions 3-, 6-, 3,6-, 3,7-, and 6,7- that were suitable for studies in synergism …

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Preparation And Fungitoxicity Of Some Trichloro-, Tribromo-, Tetrachloro-, And Tetrabromo-8-Quinolinols / Herman Gershon, Donald D. Clarke, And Muriel Gershon Department Of Chemistry, Fordham University, Bronx, New York 10458-9993 Usa, New York Botanical Garden, Bronx, New York 10458-9993 Usa, Herman Gershon, Donald Dudley Clarke Phd, Muriel Gershon Jan 2001

Preparation And Fungitoxicity Of Some Trichloro-, Tribromo-, Tetrachloro-, And Tetrabromo-8-Quinolinols / Herman Gershon, Donald D. Clarke, And Muriel Gershon Department Of Chemistry, Fordham University, Bronx, New York 10458-9993 Usa, New York Botanical Garden, Bronx, New York 10458-9993 Usa, Herman Gershon, Donald Dudley Clarke Phd, Muriel Gershon

Chemistry Faculty Publications

3,5,6-, 3,5,7-, 4,5,7-, and 5,6,7-trichloro- and -tribromo-8-quinolinols as well as 3,5,6,7- tetrachloro- and -tetrabromo-8-quinolinols were prepared and tested against six fungi (Aspergillus niger, Aspergillus oryzae, Myrothecium verrucaria, Trichoderma viride, Mucor cirinelloides, and Trichophyton mentagrophytes) in Sabouraud dextrose broth. The compounds strongly inhibit five fungi but not M. cirinelloides. They are less active than the related dichloro-8-quinolinols which is attributed to steric hindrance

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Control Of Phytoplankton Growth By Iron And Silicic Acid Availability In The Subantarctic Ocean: Experimental Results From The Saz Project, D. A. Hutchins, Peter N. Sedwick, G. R. Ditullio, P. W. Boyd, B. Queguiner, F. B. Griffiths, C. Crossley Jan 2001

Control Of Phytoplankton Growth By Iron And Silicic Acid Availability In The Subantarctic Ocean: Experimental Results From The Saz Project, D. A. Hutchins, Peter N. Sedwick, G. R. Ditullio, P. W. Boyd, B. Queguiner, F. B. Griffiths, C. Crossley

OES Faculty Publications

Subantarctic Southern Ocean surface waters in the austral summer and autumn are characterized by high concentrations of nitrate and phosphate but low concentrations of dissolved iron (Fe, similar to0.05 nM) and silicic acid (Si, <1 muM). During the Subantarctic Zone AU9706 cruise in March 1998 we investigated the relative importance of Fe and Si in controlling phytoplankton growth and species composition at a station within the subantarctic water mass (46.8degreesS, 142degreesE) using shipboard bottle incubation experiments. Treatments included unamended controls; 1.9 nM added iron (+Fe); 9 muM added silicic acid (+Si); and 1.9 nM addediron plus 9 muM added silicic acid (+Fe+Si). We followed a detailed set of biological and biogeochemical parameters over 8 days. Fe added alone clearly increased community growth rates and nitrate drawdown and altered algal community composition relative to control treatments. Surprisingly, small, lightly silicified pennate diatoms grew when Fe was added either with or without Si, despite the extremely low ambient silicic acid concentrations. Pigment analyses suggest that lightly silicified chrysophytes (type 4 haptophytes) may have preferentially responded to Si added either with or without Fe. However, for many of the parameters measured the +Fe+Si treatments showed large increases relative to both the +Fe and +Si treatments. Our results suggest that iron is the proximate limiting nutrient for chlorophyll production, photosynthetic efficiency, nitrate drawdown, and diatom growth, but that Si also exerts considerable control over algal growth and species composition. Both nutrients together are needed to elicit a maximum growth response, suggesting that both Fe and Si play important roles in structuring the subantarctic phytoplankton community.

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Effects Of Iron, Silicate, And Light On Dimethylsulfoniopropionate Production In The Australian Subantarctic Zone, G. R. Ditullio, P. N. Sedwick, D. R. Jones, P. W. Boyd, A. C. Crossley, D. A. Hutchins Jan 2001

Effects Of Iron, Silicate, And Light On Dimethylsulfoniopropionate Production In The Australian Subantarctic Zone, G. R. Ditullio, P. N. Sedwick, D. R. Jones, P. W. Boyd, A. C. Crossley, D. A. Hutchins

OES Faculty Publications

Shipboard bottle incubation experiments were performed to investigate the effects of iron, light, and silicate on algal production of particulate dimethylsulfoniopropionate (DMSPp) in the Subantarctic Zone (SAZ) south of Tasmania during March 1998. Iron enrichment resulted in threefold to ninefold increases in DMSPp concentrations relative to control treatments, following 7 and 8-day incubation experiments. Additions of Fe and Si preferentially stimulated the growth of lightly-silicified pennate diatoms and siliceous haptophytes, respectively, to which we attribute the increased DMSPp production in the incubation bottles. Both of these algal groups were previously believed to be low DMSPp …

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Analysis Of Wine For Penicillin, Gary Morris, James Yuan, Roy Williams Jan 2001

Analysis Of Wine For Penicillin, Gary Morris, James Yuan, Roy Williams

Chemistry & Biochemistry Faculty Publications

This study addresses the question of whether the antibiotic Penicillin, which is produced by the common mold Penicillium notatum, could possibly become a contaminate of wine during the fermentation process. The significance of this study is related to the potential health effects this agent might produce in those consumers who have an allergic response to Penicillin. It has been estimated that between 6% and 8% of the American population is subject to this type of allergic response. A method is developed for the detection of penicillin in wines using high-pressure liquid chromatography. We demonstrate that penicillin G hydrolyzes rapidly …

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Use Of Py-Gc/Ms Analysis Techniques In Animal Waste Management: A Preliminary Survey Of Dairy Manures, Daniel L. Vaughn, Michael A. Kruge Jan 2001

Use Of Py-Gc/Ms Analysis Techniques In Animal Waste Management: A Preliminary Survey Of Dairy Manures, Daniel L. Vaughn, Michael A. Kruge

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The increasing practice of industrial-scale agriculture tends to concentrate large masses of animal waste in relatively compact areas, potentially leading to excessive release of polluting nutrients into waterways during major storms. Anaerobic treatment conditions are generally favored to conserve nitrate N as an agricultural commodity. However, overall N contents in waste are often in excess of crop fertilization needs: storing excess N in soluble nitrate form increases pollution potential. Thus the perceived needs of agriculture and society-at-large become at odds. Organic nitrogen forms (e.g., proteins) are more environmentally stable and are less subject to unintentional release. Although U.S. farmers tend …

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