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Articles 541 - 570 of 582

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

Epichlorohydrin Cross-Linking Of Synthetic Dna Oligomers, Rami W. Zaharan, Julie T. Millard Jan 2006

Epichlorohydrin Cross-Linking Of Synthetic Dna Oligomers, Rami W. Zaharan, Julie T. Millard

Undergraduate Research Symposium (UGRS)

Epichlorohydrin (ECH), an important chemical in the synthetic polymer industry, is a bifunctional alkylating agent with the potential to form DNA interstrand crosslinks. Occupational exposure to this suspect carcinogen leads to chromosomal aberrations, and ECH has been shown to undergo reaction with DNA in vivo and in vitro. We are using denaturing polyacrylamide gel electrophoresis to assess cross-linking of synthetic DNA oligomers by both ECH and the related compound, epibromohydrin (EBH). Both epihalohydrins produce a low-mobility band on denaturing gels consistent with an interstrand cross-link. Moreover, the efficiencies, sequence preferences, reaction kinetics, and pH dependence differ for the two compounds, …


A Critical Role For Kalirin In Ngf Signaling Through Trka, Kausik Chakrabarti, Rong Lin, Noraisha I. Schiller, Yanping Wang, David Koubi, Ying-Xin Fan, Brian B. Rudkin, Gibbes R. Johnson, Martin R. Schiller Jun 2005

A Critical Role For Kalirin In Ngf Signaling Through Trka, Kausik Chakrabarti, Rong Lin, Noraisha I. Schiller, Yanping Wang, David Koubi, Ying-Xin Fan, Brian B. Rudkin, Gibbes R. Johnson, Martin R. Schiller

Life Sciences Faculty Research

Kalirin is a multidomain guanine nucleotide exchange factor (GEF) that activates Rho proteins, inducing cytoskeletal rearrangement in neurons. Although much is known about the effects of Kalirin on Rho GTPases and neuronal morphology, little is known about the association of Kalirin with the receptor/signaling systems that affect neuronal morphology. Our experiments demonstrate that Kalirin binds to and colocalizes with the TrkA neurotrophin receptor in neurons. In PC12 cells, inhibition of Kalirin expression using antisense RNA decreased nerve growth factor (NGF)-induced TrkA autophosphorylation and process extension. Kalirin overexpression potentiated neurotrophin-stimulated TrkA autophosphorylation and neurite outgrowth in PC12 cells at a low …


Crystallization And Preliminary X-Ray Analysis Of Na-Asp-1, A Multi-Domain Pathogenesis-Related-1 Protein From The Human Hookworm Parasite Necator Americanus, Oluwatoyin A. Asojo, Alex Loukas, Mehmet Inan, Rick Barent, Jicai Huang, Brad Plantz, Amber Swanson, Mark Gouthro, Michael M. Meagher, Peter J. Hotez Jan 2005

Crystallization And Preliminary X-Ray Analysis Of Na-Asp-1, A Multi-Domain Pathogenesis-Related-1 Protein From The Human Hookworm Parasite Necator Americanus, Oluwatoyin A. Asojo, Alex Loukas, Mehmet Inan, Rick Barent, Jicai Huang, Brad Plantz, Amber Swanson, Mark Gouthro, Michael M. Meagher, Peter J. Hotez

Department of Chemical and Biomolecular Engineering: Faculty Publications

Human hookworm infection is a major cause of anemia and malnutrition in the developing world. In an effort to control hookworm infection, the Human Hookworm Vaccine Initiative has identified candidate vaccine antigens from the infective larval stage (L3) of the parasite, including a family of pathogenesis-related-1 (PR-1) proteins known as the ancylostoma-secreted proteins (ASPs). The functions of the ASPs are unknown. In addition, it is unclear why some ASPs have one while others have multiple PR-1 domains. There are no known structures of a multi-domain ASP and in an effort to remedy this situation, recombinant Na-ASP-1 has been expressed, …


A Subgroup Algorithm To Identify Cross-Rotation Peaks Consistent With Non-Crystallographic Symmetry, Ryan H. Lilien, Chris Bailey-Kellogg, Amy C. Anderson, Bruce R. Donald Mar 2004

A Subgroup Algorithm To Identify Cross-Rotation Peaks Consistent With Non-Crystallographic Symmetry, Ryan H. Lilien, Chris Bailey-Kellogg, Amy C. Anderson, Bruce R. Donald

Dartmouth Scholarship

Molecular replacement (MR) often plays a prominent role in determining initial phase angles for structure determination by X-ray crystallography. In this paper, an efficient quaternion-based algorithm is presented for analyzing peaks from a cross-rotation function in order to identify model orientations consistent with proper non-crystallographic symmetry (NCS) and to generate proper NCS-consistent orientations missing from the list of cross-rotation peaks. The algorithm, CRANS, analyzes the rotation differences between each pair of cross-rotation peaks to identify finite subgroups. Sets of rotation differences satisfying the subgroup axioms correspond to orientations compatible with the correct proper NCS. The CRANS algorithm was first …


Morphological Plasticity In The Tropical Sponge Anthosigmella Varians: Responses To Predators And Wave Energy., Malcolm Hill, April L. Hill Feb 2002

Morphological Plasticity In The Tropical Sponge Anthosigmella Varians: Responses To Predators And Wave Energy., Malcolm Hill, April L. Hill

Biology Faculty Publications

The goal of the research presented here was to examine phenotypic plasticity exhibited by three morphotypes of the common Caribbean sponge Anthosigmella varians (Duchassaing & Michelotti). We were interested in examining the biotic (and, to a lesser extent, abiotic) factors responsible for branch production in this species. We also tested the hypothesis that the skeleton may serve an antipredator function in this sponge, focusing on vertebrate fish predators (i.e., angelfish) in this work. In transplant and caging experiments, unprotected forma varians replicates were immediately consumed by angelfish, while caged replicates persisted on the reef for several months. These findings support …


Effect Of Forskolin On Actin Polymerization In Cultured Vascular Smooth Muscle, Mary Janay Bailey Jan 2001

Effect Of Forskolin On Actin Polymerization In Cultured Vascular Smooth Muscle, Mary Janay Bailey

Theses, Dissertations and Capstones

Increases in intracellular cyclic AMP levels have been shown to affect vascular smooth muscle morphology. In the present study, effects of elevated cyclic AMP levels on actin polymerization were assessed to determine whether cyclic AMP induces specific changes in cytoskeletal proteins of vascular smooth muscle cells. Forskolin was used to increase intracellular cyclic AMP levels through direct activation of adenylate cyclase. Light and Electron microscopy was employed to appraise changes in the shape of vascular smooth muscle cells. Confocal microscopy was used to reveal cytoskeletal changes after exposure to M forskolin for increasing intervals of time. Differences in the expression …


Effects Of Antimetabolites On Sclerotium Rolfsii Growth And Oxalic Acid Production, Ezikiel Okafor-Agilo Jan 2001

Effects Of Antimetabolites On Sclerotium Rolfsii Growth And Oxalic Acid Production, Ezikiel Okafor-Agilo

Seton Hall University Dissertations and Theses (ETDs)

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Determining The Phylogenetic Relationships Among The Northern Pike (Esox Lucius), The Muskellunge (Esox Masquinongy), And The Silver Pike, Steven W. Foster Jan 2000

Determining The Phylogenetic Relationships Among The Northern Pike (Esox Lucius), The Muskellunge (Esox Masquinongy), And The Silver Pike, Steven W. Foster

Theses, Dissertations and Capstones

Prioritization of taxa has become a necessity due to limited resources available for conservation. Conservation efforts are often concentrated on those threatened and endangered species with the highest taxonomic importance. The silver pike is a rare game fish, often accounting for less than 1% of a total pike population where it is found. Although silver pike are normally found in association with northern pike, they have distinct morphological characteristics and have not been shown to hybridize with the northern pike. Still, many fisheries biologists consider the silver pike to be a color variant of the northern pike, and to date …


Response Properties Of Tibial Campaniform Sensilla On The Cockroach Leg In Restrained Preparations And Freely Moving Animals, Angela L. Ridgel Jan 2000

Response Properties Of Tibial Campaniform Sensilla On The Cockroach Leg In Restrained Preparations And Freely Moving Animals, Angela L. Ridgel

Theses, Dissertations and Capstones

The ability to detect changes in forces is important for effective use of a leg in posture and locomotion. This thesis examines how forces are detected in the legs of cockroaches by tibial campaniform sensilla. Campaniform sensilla are mechanoreceptors that encode forces through ovoid cuticular caps embedded in the exoskeleton. The tibial sensilla are unique in that they consist of two subgroups with mutually perpendicular cap orientations.

We characterized the responses of the tibial receptors in restrained preparations by applying forces to the leg at controlled magnitudes and rates. The tibial sensilla, as a group, were sensitive to increasing and …


The Holliday Junction In An Inverted Repeat Dna Sequence: Sequence Effects On The Structure Of Four-Way Junctions, Brandt F. Eichman, Jeff Vargason, Blaine H.M. Mooers, P. Shing Ho Jan 2000

The Holliday Junction In An Inverted Repeat Dna Sequence: Sequence Effects On The Structure Of Four-Way Junctions, Brandt F. Eichman, Jeff Vargason, Blaine H.M. Mooers, P. Shing Ho

Faculty Publications - Department of Biological & Molecular Science

Holliday junctions are important structural intermediates in recombination, viral integration, and DNA repair. We present here the single-crystal structure of the inverted repeat sequence d(CCGGTACCGG) as a Holliday junction at the nominal resolution of 2.1 Å. Unlike the previous crystal structures, this DNA junction has B-DNA arms with all standard Watson–Crick base pairs; it therefore represents the intermediate proposed by Holliday as being involved in homologous recombination. The junction is in the stacked-X conformation, with two interconnected duplexes formed by coaxially stacked arms, and is crossed at an angle of 41.4° as a right-handed X. A sequence comparison with previous …


Interaction Of Laminin Beta2 With Eps8 And Desmin In Muscle Cells, Luke Xueliang Cui Jan 1999

Interaction Of Laminin Beta2 With Eps8 And Desmin In Muscle Cells, Luke Xueliang Cui

Theses, Dissertations and Capstones

Laminin β2 is localized to the synaptic basal lamina (BL) in muscle and glomerular BL in kidney. To find interacting proteins, a mouse kidney cDNA library was screened with domain I of rat laminin β2 using the yeast two-hybrid system. Fifteen positive clones were found. The DNA sequence of three each of these clones corresponded to the phosphoprotein Eps8 (epidermal growth factor receptor pathway substrate clone 8, which is tyrosine phosphorylated after EGF stimulation) and the intermediate filament (IF) protein keratin. To determine if this interaction occurred in muscle cells, C2 cells transfected with the rat …


Benthic Biodiversity And Physico-Chemical Parameters Of Acid Mine Drainage, Acid Impacted And Nonimpacted Streams, Stephen D. Greene Jan 1999

Benthic Biodiversity And Physico-Chemical Parameters Of Acid Mine Drainage, Acid Impacted And Nonimpacted Streams, Stephen D. Greene

Theses, Dissertations and Capstones

South Fork of Sand Lick Creek, Logan County, West Virginia, drains an abandoned coal strip mine which had exploited Pottsville series coalbeds (Pennsylvania strata). These strata outcrop throughout southwestern West Virginia. North Fork watershed is relatively unchanged, save a small roadcut throughout. South Fork benthic community had not recovered although mining activity had ceased about 20 years earlier. Benthic communities were analyzed with detrended correspondence analysis (DCA). Family Chironomidae predominated South Fork benthic community throughout the study. North Fork’s benthic community had as major contributors acid resistant caddisfly family Hydropsychidae, mayfly family Baetidae, and stonefly families Perlodidae and Nemouridae. Family …


Clarification Of The Hybrid Origin Of Carex X Deamii Herm. (Cyperaceae) Based On Macro And Micro Morphological Characters, Paul B. Marcum Jan 1999

Clarification Of The Hybrid Origin Of Carex X Deamii Herm. (Cyperaceae) Based On Macro And Micro Morphological Characters, Paul B. Marcum

Theses, Dissertations and Capstones

The origin of Carex x deamii Herm. has been in question ever since it was named to science in 1938. Collections of the hybrid have always been associated with C. shortiana Dewey and either C. typhina Michx. or C. squarrosa L.. C. typhina and C. squarrosa are closely related taxa (Section Squarrosae) and often are morphologically similar. Because of this similarity, determining the correct parental species to the hybrid has been extremely difficult. It is known that the hybrid is sterile and only reproduces asexually. Pollen was analyzed to ascertain the viability of all four taxa. This study utilizes both …


Fabrication Of Protein Arrays Using Electron Beam Lithography, Duy-Bao Phan Dinh Jan 1999

Fabrication Of Protein Arrays Using Electron Beam Lithography, Duy-Bao Phan Dinh

Theses, Dissertations and Capstones

Very few electron beam based methods for producing high-resolution patterns of surface bound proteins on glass have been developed.

There are only two types of end groups at the surface of glass, they are silanol and siloxane groups. An estersil layer can be formed on the surface of glass by treatment with hot alcohol creating a hydrophobic layer. The reaction is depicted as follows.

-Si-OH + HOR -SiO-R +H2O R = alkyl chain

The proposal that protein arrays could be fabricated by patterned electron bombardment using estersils as a negative resist was tested in this research. The hydrophobic estersil layer …


The Role Of Domain I In Laminin Chain Assembly, George D. Kamphaus Jan 1998

The Role Of Domain I In Laminin Chain Assembly, George D. Kamphaus

Theses, Dissertations and Capstones

Laminin, a major component of basement membrane, is a trimeric glycoprotein comprised of three chains - α, β and γ (Burgeson et al., 1994). An order for trimer assembly has been deduced: first, the β and γ chains bind to form a dimer and subsequently α is added to complete the trimer (I. Hunter et al., 1990 & 1992; Utani et al., 1994 & 1995). The C-terminal portions, found within the protein structural domain I of the p and y chains, are implicated in dimer and trimer formation by biochemical studies performed extracellularly (Utani, et al., 1994 & 1995; Nomizu …


Type I Camp-Dependent Protein Kinase Delays Apoptosis In Human Neutrophils At A Site Upstream Of Caspase-3, Lav K. Parvathenani, E. Stephen Buescher, Enrique Chacon-Cruz, Stephen J. Beebe Jan 1998

Type I Camp-Dependent Protein Kinase Delays Apoptosis In Human Neutrophils At A Site Upstream Of Caspase-3, Lav K. Parvathenani, E. Stephen Buescher, Enrique Chacon-Cruz, Stephen J. Beebe

Bioelectrics Publications

Current data suggest that apoptosis controls neutrophil numbers in tissues. We analyzed roles for and the sites of action for the cAMP-dependent protein kinases (cAPKs) in apoptosis induced in human neutrophils by in vitro storage, cycloheximide (CHX) exposure, and anti-Fas exposure. Treatment with 8-chlorophenylthio-cAMP (8-CPT-cAMP) prolonged the time required for 50% of the cells to exhibit apoptotic morphology (t 50) from 16.3 to 41.8 h (in vitro culture), from 2.4 to 7.8 h (CHX), and from 4.8 to 6.5 h (anti-Fas). CHX ± 8-CPT-cAMP did not significantly alter resting intracellular calcium levels and H-89, a selective inhibitor of cAPK, had …


Effect Of Cocaine On Rabbit Renin Angiotensin System: Cocaine Detection In Adult And Fetal Tissue And Adult Plasma Using Ion Mobility Spectrometry, Barbara Belinda Guinn Jul 1997

Effect Of Cocaine On Rabbit Renin Angiotensin System: Cocaine Detection In Adult And Fetal Tissue And Adult Plasma Using Ion Mobility Spectrometry, Barbara Belinda Guinn

Biological Sciences Theses & Dissertations

Ion mobility spectrometry (IMS) was used to detect cocaine and/or the metabolite ecgonine methyl ester (EME) in tissue and plasma samples from male, maternal, and fetal New Zealand White (NZW) rabbits. EME was consistently detected in all adult plasma samples 5 minutes after the injection of cocaine hydrochloride (cocaine•HCI, 2 mg/kg). EME was also in the liver, kidneys, testicles, and ovaries. Five minutes after the injection of cocaine•HCI, the male arterial pressure (MAP) increased from a mean control value of 79 ± 3.2 mmHg to 88 ± 4.1 mmHg, and the pCO2 increased from a control value of28 ± …


Effects Of Creatine Supplementation On Muscular Strength And Power Development In Well-Trained Football Players, Josef D. Mcquain Jan 1997

Effects Of Creatine Supplementation On Muscular Strength And Power Development In Well-Trained Football Players, Josef D. Mcquain

Theses, Dissertations and Capstones

The purpose of this study was to determine the effects of creatine supplementation on strength and power performance in well-trained football players. Twenty-one subjects were randomly assigned to three treatment groups: 1) creatine monohydrate, 2) creatine monohydrate+dextrose, or 3) placebo utilizing a double-blind design. Prior to assignment, subjects were matched according to lean body mass. After a five day loading dose, a maintenance dose was administered for 12 days. Test protocols included three anaerobic work bouts: l) two 30 s Wingate bike tests interspersed with five minutes recovery were used to ascertain relative and absolute power, 2) two 100 yard …


An Immunomodulating Mycotoxin Interferes With The Development Of Autoimmune Diabetes In Diabetes-Prone Bb/Wor Rats, Honggang Liu Jan 1997

An Immunomodulating Mycotoxin Interferes With The Development Of Autoimmune Diabetes In Diabetes-Prone Bb/Wor Rats, Honggang Liu

Theses, Dissertations and Capstones

Various fungal products have immunomodulating activity and some have been studied regarding prevention of transplantation rejection. Prior to this investigation, the mycotoxin, gliotoxin (GT), has never been investigated as an immunotherapeutic drug for autoimmune disease. GT is a fungal secondary metabolite and a member of the epipolythiodioxopiperazine (ETP) family which has been shown to inhibit phagocytosis, induction of cytolytic T cells and the proliferation of T cells following mitogen stimulation. GT also induces in vitro apoptosis in certain immune cell types. More importantly, GT exhibits selective activity towards cells of hemopoietic origin.

Autoimmune diseases are disorders caused by immune responses …


The Regulation Of Glucose Transport In Cultured Vascular Smooth Muscle Cells By Angiotensin Ii And Glucose, Leslie Ann Quinn Jan 1997

The Regulation Of Glucose Transport In Cultured Vascular Smooth Muscle Cells By Angiotensin Ii And Glucose, Leslie Ann Quinn

Theses, Dissertations and Capstones

Glucose transport was assessed in vascular smooth muscle (VSM) cells by measuring the uptake of a radiolabeled non-metabolizable glucose analog, [3H]-2-deoxglucose. VSM cells, isolated from rat aortae by enzymatic digestion, were maintained in culture in Dulbecco's Modified Eagle Medium supplemented with 10% newborn calf serum at 37°C with 5% CO2 and air. Angiotensin II (AU) increased glucose transport by 84%. Significant stimulation occurred by two hours of exposure with the maximum effect being observed between six and eight hours. All effects were concentration dependent with a threshold response being detected at 0.1 nM. All-stimulated transport was blocked by an AU …


Description Of Tadpoles Of Three Species Of Scinax (Anura: Hylidae), Rafael O. De Sá, Rocjard Wassersig, Arturo I. Kehr Jan 1997

Description Of Tadpoles Of Three Species Of Scinax (Anura: Hylidae), Rafael O. De Sá, Rocjard Wassersig, Arturo I. Kehr

Biology Faculty Publications

Larval morphological characteristics have been used to cluster species of Scinax in seven species groups and to support the monophyly of some of these groups. However, our present knowledge of Scinax tadpoles is incomplete; currently, tadpoles of only 21 of the approximately 80 recognized species have been described. Herein, we describe and illustrate the external morphology and oral disc characteristics of larval Scinax berthae, S. nebulosa, and S. boesemani. The presence of a "labial arm" supporting the P3 tooth row in S. boesemani, and its absence from S. nebulosa, is discussed in the light of our limited knowledge of tadpoles …


Effect Of Retinoic Acid On The Expression And Function Of Ap-1 Transcription Factor In B16 Mouse Melanoma Cells: Role Of Protein Kinase, Sejal H. Desai Jan 1996

Effect Of Retinoic Acid On The Expression And Function Of Ap-1 Transcription Factor In B16 Mouse Melanoma Cells: Role Of Protein Kinase, Sejal H. Desai

Theses, Dissertations and Capstones

Retinoic acid (RA) induces differentiation of B16 mouse melanoma cells. This differentiation is accompanied by an increase in protein kinase Ca (PKCα) protein level and selective enrichment in nuclear-associated PKCα. PKC is thought to regulate gene expression through the TPA response element (TRE). This element is specifically recognized by the AP-1 transcription factor composed of jun and fos family members. In this study, I have analyzed the effect of RA on the expression and function of AP-1 in B16 mouse melanoma cells. Transient transfection analysis of B16 cells using leuciferase reporter gene constructs with or without AP-1 elements indicated that …


Regulation Of Melanogenesis In B16 Mouse Melanoma Cells By Protein Kinase C (Pkc), Harish Mahalingam Jan 1996

Regulation Of Melanogenesis In B16 Mouse Melanoma Cells By Protein Kinase C (Pkc), Harish Mahalingam

Theses, Dissertations and Capstones

The pigment cell-specific expression of tyrosinase and TRP1 has been shown to be important for the production of melanin in pigmented cells. Using a pigmented cell line, B16 mouse melanoma, we obtained evidence that PKC plays a major role in regulating melanogenesis. Chronic treatment with phorbol dibutyrate (PDBu) leads to downregulation of PKC activity and protein levels. This is accompanied by a loss of pigmentation which is correlated with a 50% reduction and a complete loss of TRP1 and tyrosinase respectively. Similar results were obtained with Northern and Western blotting indicating that PKC may regulate the steady state levels of …


Morfología Y Moléculas: Bases Complementarias De La Sistemática Moderna, Rafael O. De Sá, David M. Hillis Jan 1993

Morfología Y Moléculas: Bases Complementarias De La Sistemática Moderna, Rafael O. De Sá, David M. Hillis

Biology Faculty Publications

RESUMEN

El auge de las técnicas moleculares en las últimas dos décadas ha traído nuevos enfoques en los estudios sistemáticos. Aquí presentaremos una revisión del uso, las aplicaciones, y los problemas de las principales metodologías de trabajo. Cada una de estas técnicas es aplicable a algunos problemas e inapropiada para otros, y es importante entender las suposiciones y limitaciones de cada técnica. Concluimos que el uso combinado de los enfoques morfológicos y moleculares otorga mejor resolución a los problemas sistemáticos.

ABSTRACT

The development of molecular techniques during the last two decades has brought new approaches to the analysis of systematic …


The Cγ Subunit Is A Unique Isozyme Of The Camp-Dependent Protein Kinase, Stephen J. Beebe, Paul Salomonsky, Tore Jahnsen, Yixin Li Jan 1992

The Cγ Subunit Is A Unique Isozyme Of The Camp-Dependent Protein Kinase, Stephen J. Beebe, Paul Salomonsky, Tore Jahnsen, Yixin Li

Bioelectrics Publications

There are at least three isozymes (Cα, Cβ, and Cγ) of the mammalian catalytic (C) subunit of cAMP-dependent protein kinase (PKA) (Beebe, S., Oyen, O., Sandberg, M., Froysa, A., Hansson, V., and Jahnsen, T. (1990) Mol. Endocrinol. 4, 465-475). To compare the Cγ and Cα isozymes, the respective cDNAs were expressed in permanently transformed Kin-8 PKA-deficient Y1 adrenal cells using the mouse metallothionein promoter. The recombinant C subunits were characterized as immunoreactive, zinc-inducible, cAMP-dependent kinase activities. In contrast to Cα, histone was a better substrate than Leu-Arg-Arg-Ala-Ser-Leu-Gly (Kemptide) for Cγ. Furthermore, Cγ histone kinase activity was not inhibited by the …


Cell Surface-Binding Sites For Progesterone Mediate Calcium Uptake In Human Sperm, Peter F. Blackmore, Joseph Neulan, Frank Lattanzio, Stephen J. Beebe Jan 1991

Cell Surface-Binding Sites For Progesterone Mediate Calcium Uptake In Human Sperm, Peter F. Blackmore, Joseph Neulan, Frank Lattanzio, Stephen J. Beebe

Bioelectrics Publications

Recent studies (e.g. Blackmore, P. F., Beebe, S. J., Danforth, D. R., and Alexander, N.) (1990) J. Biol. Chem. 265, 1376-1380) have shown that in human sperm, progesterone produces a rapid increase in intracellular free calcium ([Ca2+]i) and an induction of the acrosome reaction (e.g. Osman, R. A., Andria, M. L., Jones, A. D., and Meizel, S. (1989) Biochem. Biophys. Res. Commun. 160, 828-833). In this study, the location of progesterone receptors on the cell surface of human sperm was identified using progesterone immobilized on bovine serum albumin (BSA) (progesterone 3-(O-carboxymethyl)oxime:BSA) as well as progesterone and its 3-O-carboxymethyloxime derivative. Using …


Conformational And Circular Dichroism Studies On N-Acetyl-L-Prolyl-D-Alanyl-Methylamide, S. Ramaprasad Jan 1990

Conformational And Circular Dichroism Studies On N-Acetyl-L-Prolyl-D-Alanyl-Methylamide, S. Ramaprasad

Journal of the Arkansas Academy of Science

The compact ordered conformations of the molecule N-Acteyl-L-Prolyl-D-Alanyl-Methylamide have been studied by semiempirical energy calculations in vacuum and circular dichroism (CD) in solution. The presence of ordered structure has been observed in hydrogen bond promoting solvents like trifluoroethanol by CD studies. In hydrogen bond breaking solvents, like trifluoroacetic acid (TFA), significant fraction of the ordered conformers probably assume extended conformation without intramolecular hydrogen bonds and perhaps are in equilibrium with the fraction of compact ordered structures. The trend observed in going from nonpolar to polar solvent is also compatible with the previous NMR studies in solution. The semiempirical energy calculations …


Progesterone And 17 Α-Hydroxyprogesterone: Novel Stimulators Of Calcium Influx In Human Sperm, Peter F. Blackmore, Stephen J. Beebe, Douglas R. Danforth, Nancy Alexander Jan 1990

Progesterone And 17 Α-Hydroxyprogesterone: Novel Stimulators Of Calcium Influx In Human Sperm, Peter F. Blackmore, Stephen J. Beebe, Douglas R. Danforth, Nancy Alexander

Bioelectrics Publications

Progesterone and 17 alpha-hydroxyprogesterone (but not other steroids such as testosterone, corticosterone, beta-estradiol, estrone, dehydroepiandrosterone, 20 alpha-hydroxypregnen-3-one, androstenedione, and pregnenolone) were shown to cause an immediate increase, in free cytosolic calcium ([Ca2+]i) in both capacitated and noncapacitated human sperm, using the fluorescent indicator fura 2. Significant increases in [Ca2+]i were observed with 10 ng/ml progesterone, while maximum effects were seen with 1 microgram/ml progesterone. Two other steroids 11 beta-hydroxyprogesterone and 5 alpha-pregnane-3,20-dione exhibited significant activity to increase [Ca2+]i. This increase in [Ca2+]i elicited by progesterone was entirely due to Ca2+ influx from the extracellular medium since the increase in [Ca2+]i …


The Characterization Of Ribosomal Rna Gene Chromatin From Physarum Polycephalum, Sally A. Amero, Vicky L. Montoya, Wendy L. Murdoch, Roy C. Ogle, John L. Keating, Robert M. Grainger Aug 1988

The Characterization Of Ribosomal Rna Gene Chromatin From Physarum Polycephalum, Sally A. Amero, Vicky L. Montoya, Wendy L. Murdoch, Roy C. Ogle, John L. Keating, Robert M. Grainger

School of Medical Diagnostics & Translational Sciences Publications

We have isolated ribosomal RNA gene (rDNA) chromatin from Physarum polycephalum using a nucleolar isolation procedure that minimizes protein loss from chromatin and, subsequently, either agarose gel electrophoresis or metrizamide gradient centrifugation to purify this chromatin fraction (Amero, S. A., Ogle, R. C., Keating, J. L., Montoya, V. L., Murdoch, W. L., and Grainger, R. M. (1988) J. Biol. Chem. 263, 10725-10733). Metrizamide-purified rDNA chromatin obtained from nucleoli isolated according to the new procedure has a core histone/DNA ratio of 0.77:1. The major core histone classes comigrate electrophoretically with their nuclear counterparts on Triton-acid-urea/sodium dodecyl sulfate two-dimensional gels, although they …


A Light And Electron Microscopic Study Of The Rat Olfactory Tubercle: Normal Morphology And Acetylcholinesterase Localization, James Curtis Woodley Jul 1988

A Light And Electron Microscopic Study Of The Rat Olfactory Tubercle: Normal Morphology And Acetylcholinesterase Localization, James Curtis Woodley

Biological Sciences Theses & Dissertations

A cytoarchitectural analysis of the rat olfactory tubercle using Nissl-stained coronal sections revealed that the dense cell layer (DCL) consisted of medium sized striatal cells in the cortical regions and small sized "granule" cells in the cap regions. Also delineated from this experiment was a rim of neuropil, nearly devoid of neurons as well as neuronal processes, outlining the islands of Calleja. Acetylcholinesterase (AChE) localization utilizing light microscopy revealed that the olfactory tubercles (OT) contained AChE-positive fibers that were orientated dorsoventrally in the molecular and multiform layers. The DCL consisted of only fibers en passant and putative terminals. Diisopropylfluorophosphate (DFP) …