Medical Specialties Commons^™

Beta-Galactosidase As A Marker Of Ischemic Injury And A Mechanism For Viability Assessment In Porcine Liver Transplantation., Shawn D. St Peter, Charles J. Imber, Inigo Lopez De Cenarruzabeitia, James Mcguire, Tim James, Richard Taylor, Peter J. Friend

Manuscripts, Articles, Book Chapters and Other Papers

Glycohydrolases are a group of enzymes contained predominantly within lysosomes, which are released during Kupffer cell activation or death. One of these, beta-galactosidase, has been proposed as a marker of ischemia-reperfusion injury in the liver because Kupffer cell activation represents a primary event in the injurious reperfusion cascade. In this study, we compared B-galactosidase with more traditional indicators of liver injury and function in a porcine model of liver preservation. Porcine livers were allocated into two groups: group C (n = 5), preserved in University of Wisconsin solution by standard cold storage for 24 hours, and group W (n = …

Regulation Of Type-Ii Collagen Gene Expression During Human Chondrocyte De-Differentiation And Recovery Of Chondrocyte-Specific Phenotype In Culture Involves Sry-Type High-Mobility-Group Box (Sox) Transcription Factors, David G. Stokes, Gang Liu, Rita Dharmavaram, David Hawkins, Sonsoles Piera-Velazquez, Sergio A. Jimenez

Selected Works of Sergio Jiménez, MD, MACR

During ex vivo growth as monolayer cultures, chondrocytes proliferate and undergo a process of de-differentiation. This process involves a change in morphology and a change from expression of chondrocyte-specific genes to that of genes that are normally expressed in fibroblasts. Transfer of the monolayer chondrocyte culture to three-dimensional culture systems induces the cells to re-acquire a chondrocyte-specific phenotype and produce a cartilaginous-like tissue in vitro. We investigated mechanisms involved in the control of the de-differentiation and re-differentiation process in vitro. De-differentiated chondrocytes re-acquired their chondrocyte-specific phenotype when cultured on poly-(2-hydroxyethyl methacrylate) (polyHEMA) as assayed by morphology, reverse transcriptase PCR of …

Evaluation Of Cholera Vaccines Formulated With Toxin-Coregulated Pilin Peptide Plus Polymer Adjuvant In Mice, Jia-Yan Wu, William F. Wade, Ronald K. Taylor

Dartmouth Scholarship

Cholera is an acute diarrheal disease that is caused by the gram-negative bacterium Vibrio cholerae. The low efficacy of currently available killed-whole-cell vaccines and the reactinogenicity coupled with potential reversion of live vaccines have thus far precluded widespread vaccination for the control of cholera. Recent studies on the molecular nature of the virulence components that contribute to V. cholerae pathogenesis have provided insights into possible approaches for the development of a defined subunit cholera vaccine. Genetic analysis has demonstrated that the toxin-coregulated pilus (TCP) is the major factor that contributes to colonization of the human intestine by V. cholerae. In …

Immune Response Genes Modulate Serologic Responses To Vibrio Cholerae Tcpa Pilin Peptides, Michael D. Meeks, Terri K. Wade, Ronald K. Taylor, William F. Wade

Dartmouth Scholarship

Cholera is an enteric disease caused by Vibrio cholerae. Toxin-coregulated pilus (TCP), a type 4 pilus expressed by V. cholerae, is a cholera virulence factor that is required for host colonization. The TCP polymer is composed of subunits of TcpA pilin. Antibodies directed against TcpA are protective in animal models of cholera. While natural or recombinant forms of TcpA are difficult to purify to homogeneity, it is anticipated that synthesized TcpA peptides might serve as immunogens in a subunit vaccine. We wanted to assess the potential for effects of the immune response (Ir) gene that could complicate a peptide-based …

Anti-Class Ii Monoclonal Antibody-Targeted Vibrio Cholerae Tcpa Pilin: Modulation Of Serologic Response, Epitope Specificity, And Isotype, Jia-Yan Wu, Ronald K. Taylor, William F. Wade

Dartmouth Scholarship

Toxin-coregulated pilus (TCP) is a colonization factor required for cholera infection. It is not a strong immunogen when delivered in the context of whole cells, yet pilus subunits or TcpA derivative synthetic peptides induce protective responses. We examined the efficacy of immunizing mice with TCP conjugated to anti-class II monoclonal antibodies (MAb) with or without the addition of cholera toxin (CT) or anti-CD40 MAb to determine if the serologic response to TcpA could be manipulated. Anti-class II MAb-targeted TCP influenced the anti-TCP peptide serologic response with respect to titer and isotype. Responses to TcpA peptide 4 were induced with class …

Evaluation Of A Tetracycline-Inducible Promoter In Staphylococcus Aureus In Vitro And In Vivo And Its Application In Demonstrating The Role Of Sigb In Microcolony Formation, B. T. Bateman, N. P. Donegan, T. M. Jarry, M. Palma

Dartmouth Scholarship

An inducible promoter system provides a powerful tool for studying the genetic basis for virulence. A variety of inducible systems have been used in other organisms, including pXyl-xylR-inducible promoter, the pSpac-lacI system, and the arabinose-inducible P_BAD promoter, but each of these systems has limitations in its application to Staphylococcus aureus. In this study, we demonstrated the efficacy of a tetracycline-inducible promoter system in inducing gene expression in S. aureus in vitro and inside epithelial cells as well as in an animal model of infection. Using the xyl/tetO promoter::gfp_uvr fusion carried on a shuttle …

Sensitivity Of Bovine Blastocyst Gene Expression Patterns To Culture Environments Assessed By Differential Display Rt-Pcr., D R Natale, P A De Sousa, M E Westhusin, A J Watson

Obstetrics & Gynaecology Publications

The use of culture media to support the development of preimplantation embryos to the blastocyst stage is often associated with detrimental effects on normal development. These effects have been uncovered largely by investigating the phenotypic abnormalities displayed by fetuses and newborns derived from cultured preimplantation embryos. Research to understand the impact of culture on the embryonic developmental programme has focused on embryo metabolism, gene expression and genomic imprinting. We have used differential display RT-PCR to examine culture influences on global transcript pools in bovine embryos. Others have examined culture influences on candidate "marker genes" in cultured murine, ovine and bovine …

Asymmetrical Response Of P38 Kinase Activation To Volume Changes In Primary Rat Astrocytes, Dazhong Xu, Ling Wang, James E. Olson, Luo Lu

Emergency Medicine Faculty Publications

Activation of p38 kinase by osmotic stress has been documented in many cells; however, no report has distinguished the effects of cell volume on p38 activity from the effects of the altered osmotic condition per se. Here we report asymmetrical activation of astrocyte p38 mitogen-activated protein (MAP) kinase in response to volume increases and volume decreases. We separate effects of cell volume changes from the effects of osmotic exposure on p38 activation. Exposure to 400, 500, or 600 mOsm phosphate-buffered saline (PBS) caused cell shrinkage and an osmolality-dependent increase in p38 activity to 175%, 409%, or 518%, respectively, compared with …

Cyclooxygenase-2 And Prostaglandin E(2)(Pge(2)) Receptor Messenger Rnas Are Affected By Bovine Oocyte Maturation Time And Cumulus-Oocyte Complex Quality, And Pge(2) Induces Moderate Expansion Of The Bovine Cumulus In Vitro., M D Calder, A N Caveney, M E Westhusin, A J Watson

Obstetrics & Gynaecology Publications

Expression of cyclooxygenase-2 (COX-2) and prostaglandin E(2) (PGE(2)) receptor 2 (EP2) are necessary for rodent cumulus expansion in vivo. Prostaglandin E(2) receptor 3 (EP3) has been detected in bovine preovulatory follicles and corpora lutea. The current experiments examined the effect of PGE(2) on bovine cumulus expansion in vitro and expression of COX-2, EP1, EP2, EP3, and EP4 mRNAs in bovine cumulus-oocyte complexes (COCs) at 0, 6, 12, 18, and 24 h time points during maturation in vitro. Concentrations of PGE(2) above 50 ng/ml resulted in moderate cumulus expansion of bovine COCs, but expansion did not occur in the absence of …

Amino Acid Concentrations In Fluids From The Bovine Oviduct And Uterus And In Ksom-Based Culture Media., Y M Elhassan, G Wu, A C Leanez, R J Tasca, A J Watson, M E Westhusin

Obstetrics & Gynaecology Publications

Amino acids in bovine oviductal and uterine fluids were measured and compared with those in modified simplex optimized medium (KSOM) supplemented with either fetal calf serum or Minimum Essential Medium amino acids in addition to bovine serum albumin, fetal calf serum or polyvinyl alcohol. Concentrations of cysteine, threonine, tryptophan, alanine, aspartate, glycine, glutamate, proline, beta-alanine, and citrulline were higher in oviductal fluids than in KSOM-based culture media. Nonessential and essential amino acids were present in ratios of 5:1 and 2:1 in oviductal and uterine fluids, respectively. Concentrations of alanine (3.7 mM), glycine (14.1 mM) and glutamate (5.5 mM) were high …

Regulation Of Blastocyst Formation., A J Watson, L C Barcroft

Obstetrics & Gynaecology Publications

Preimplantation or pre-attachment development encompasses the "free"-living period of mammalian embryogenesis, which directs development of the zygote through to the blastocyst stage. Blastocyst formation is essential for implantation, establishment of pregnancy and is a principal determinant of embryo quality prior to embryo transfer. Cavitation (blastocyst formation) is driven by the expression of specific sets of gene products that direct the acquisition of cell polarity within the trophectoderm, which is both the first epithelium of development and the outer cell layer encircling the inner cell mass of the blastocyst. Critical gene families controlling these events include: the E-cadherin-catenin cell adhesion family, …

Induction Of Beta3-Integrin Gene Expression By Sustained Activation Of The Ras-Regulated Raf-Mek-Extracellular Signal-Regulated Kinase Signaling Pathway., Douglas Woods, Holly Cherwinski, Eleni Venetsanakos, Arun Bhat, Stephan Gysin, Martine Humbert, Paul F. Bray, Vicki L. Saylor, Martin Mcmahon

Cardeza Foundation for Hematologic Research

Alterations in the expression of integrin receptors for extracellular matrix (ECM) proteins are strongly associated with the acquisition of invasive and/or metastatic properties by human cancer cells. Despite this, comparatively little is known of the biochemical mechanisms that regulate the expression of integrin genes in cells. Here we demonstrate that the Ras-activated Raf-MEK-extracellular signal-regulated kinase (ERK) signaling pathway can specifically control the expression of individual integrin subunits in a variety of human and mouse cell lines. Pharmacological inhibition of MEK1 in a number of human melanoma and pancreatic carcinoma cell lines led to reduced cell surface expression of alpha6- and …

Expression Of Pthrp And Pthr (Pth/Pthrp-R) Mrnas And Polypeptides In Bovine Ovary And Stimulation Of Bovine Blastocyst Development In Vitro Following Pthrp Treatment During Oocyte Maturation., P H Watson, M E Westhusin, A J Watson

Obstetrics & Gynaecology Publications

Parathyroid hormone related protein (PTHrP) and its receptor have well-established roles in the development and regulation of many tissues, including bone and mammary gland. The objectives of this study were: (1) to characterize the distribution of mRNAs encoding parathyroid hormone (PTH)-related protein (PTHrP) and receptor (PTHR) in bovine ovary; (2) to characterize the distribution of PTHrP and PTHR polypeptides in bovine ovary; (3) to examine the influences of PTHrP (1-141) treatment during bovine oocyte maturation in vitro on blastocyst development. mRNAs encoding PTHrP and PTHR were detected by in situ hybridization methods in oocytes, and granulosa cells in all follicles …

Mrnas Encoding Aquaporins Are Present During Murine Preimplantation Development., H Offenberg, L C Barcroft, A Caveney, D Viuff, P D Thomsen, A J Watson

Obstetrics & Gynaecology Publications

The present study was conducted to investigate the mechanisms underlying fluid movement across the trophectoderm during blastocyst formation by determining whether aquaporins (AQPs) are expressed during early mammalian development. AQPs belong to a family of major intrinsic membrane proteins and function as molecular water channels that allow water to flow rapidly across plasma membranes in the direction of osmotic gradients. Ten different AQPs have been identified to date. Murine preimplantation stage embryos were flushed from the oviducts and uteri of superovulated CD1 mice. Reverse transcription-polymerase chain reaction (RT-PCR) methods employing primer sets designed to amplify conserved sequences of AQPs (1-9) …

Differential Involvement Of Na(+),K(+)-Atpase Isozymes In Preimplantation Development Of The Mouse., D J Macphee, D H Jones, K J Barr, D H Betts, A J Watson, G M Kidder

Obstetrics & Gynaecology Publications

Na(+),K(+)-ATPase plays an essential role in mammalian blastocoel formation (cavitation) by driving trans-epithelial sodium transport. Previously, the alpha1 and beta1 subunit isoforms of this enzyme were identified in preimplantation mouse embryos and were assumed to be responsible for this function. Here we show that mRNAs encoding an additional alpha subunit isoform (alpha3) and the remaining two beta subunit isoforms are also present in preimplantation embryos. Whereas alpha3 mRNA accumulates between the four-cell and the blastocyst stages and thus results from embryonic transcription, the same could not be demonstrated for beta2 and beta3 mRNAs. Immunoblot analyses confirmed that these subunits are …

Ubinuclein, A Novel Nuclear Protein Interacting With Cellular And Viral Transcription Factors., S Aho, M Buisson, T Pajunen, Y W Ryoo, J F Giot, H Gruffat, A Sergeant, Jouni Uitto

Department of Dermatology and Cutaneous Biology Faculty Papers

The major target tissues for Epstein-Barr virus (EBV) infection are B lymphocytes and epithelial cells of the oropharyngeal zone. The product of the EBV BZLF1 early gene, EB1, a member of the basic leucine-zipper family of transcription factors, interacts with both viral and cellular promoters and transcription factors, modulating the reactivation of latent EBV infection. Here, we characterize a novel cellular protein interacting with the basic domains of EB1 and c-Jun, and competing of their binding to the AP1 consensus site. The transcript is present in a wide variety of human adult, fetal, and tumor tissues, and the protein is …

The Pl(A2) Polymorphism Of Integrin Beta(3) Enhances Outside-In Signaling And Adhesive Functions., K Vinod Vijayan, Pascal J. Goldschmidt-Clermont, Christine Roos, Paul F. Bray

Cardeza Foundation for Hematologic Research

Genetic factors are believed to influence the development of arterial thromboses. Because integrin alpha(IIb)beta(3) plays a crucial role in thrombus formation, we analyzed receptor adhesive properties using Chinese hamster ovary and human kidney embryonal 293 cells overexpressing the Pl(A1) or Pl(A2) polymorphic forms of alpha(IIb)beta(3). Soluble fibrinogen binding was no different between Pl(A1) and Pl(A2) cells, either in a resting state or when alpha(IIb)beta(3) was activated with anti-LIBS6. Pl(A1) and Pl(A2) cells bound equivalently to immobilized fibronectin. In contrast, significantly more Pl(A2) cells bound to immobilized fibrinogen in an alpha(IIb)beta(3)-dependent manner than did Pl(A1) cells. Disruption of the actin cytoskeleton …

Impact Of Bovine Oocyte Maturation Media On Oocyte Transcript Levels, Blastocyst Development, Cell Number, And Apoptosis., A J Watson, P De Sousa, A Caveney, L C Barcroft, D Natale, J Urquhart, M E Westhusin

Obstetrics & Gynaecology Publications

The objectives were 1) to investigate the effects of oocyte maturation in serum-free and amino acid-supplemented defined media on oocyte transcript levels, blastocyst cell number, and apoptosis; 2) to investigate the influence of oocyte maturation culture atmosphere on blastocyst development, total cell number, and apoptosis; and 3) to examine the influence of epidermal growth factor (EGF) during oocyte maturation on blastocyst cell number and apoptosis. The results demonstrate that blastocysts derived from in vitro maturation, fertilization, and embryo culture protocols undergo apoptosis but that apoptotic levels are not greatly influenced by the oocyte maturation environment. Amino acid supplementation of oocyte …

Effects Of Superovulated Heifer Diet Type And Quantity On Relative Mrna Abundances And Pyruvate Metabolism In Recovered Embryos., C Wrenzycki, P De Sousa, E W Overström, R T Duby, D Herrmann, A J Watson, H Niemann, D O'Callaghan, M P Boland

Obstetrics & Gynaecology Publications

This study investigated the effects of quantity and type of diet fed to superovulated donor heifers on molecular and metabolic indices of embryonic development. These effects included the relative abundances of mRNAs for the alpha 1 subunit of Na/K-ATPase and the antioxidant enzyme Cu/Zn-SOD, as well as pyruvate utilization in bovine morulae and blastocysts developed in vivo. Heifers were fed a daily ration of either grass silage and a citrus-beet pulp-based concentrate or grass silage and a barley-based concentrate for 116 days, both at 3 kg per day or ad libitum. In embryos derived from heifers fed the pulp-based diets, …

Insulin-Like Growth Factor Ii Signaling In Neoplastic Proliferation Is Blocked By Transgenic Expression Of The Metalloproteinase Inhibitor Timp-1, David C. Martin, John L. Fowlkes, Bojana Babic, Rama Khokha

Pediatrics Faculty Publications

Insulin-like growth factor (IGF) II is overexpressed in many human cancers and is reactivated by, and crucial for viral oncogene (SV40 T antigen, [TAg])-induced tumorigenesis in several tumor models. Using a double transgenic murine hepatic tumor model, we demonstrate that tissue inhibitor of metalloproteinase 1 (TIMP-1) blocks liver hyperplasia during tumor development, despite TAg-mediated reactivation of IGF-II. Because the activity of IGFs is controlled by IGF-binding proteins (IGFBPs), we investigated whether TIMP-1 overexpression altered the IGFBP status in the transgenic liver. Ligand blotting showed that IGFBP-3 protein levels were increased in TIMP-1-overexpressing double transgenic littermates, whereas IGFBP-3 mRNA levels were …

Global Cns Gene Transfer For A Childhood Neurogenetic Enzyme Deficiency: Canavan Disease., Paola Leone, Christopher G Janson, Scott J Mcphee, Matthew J During

Department of Neurosurgery Faculty Papers

The neurogenetic prototypic disease on which we chose to test our gene therapy strategy is Canavan disease (CD). CD is an autosomal recessive leukodystrophy associated with spongiform degeneration of the brain. At present the disease is uniformly fatal in affected probands. CD is characterized by mutations in the aspartoacylase (ASPA) gene, resulting in loss of enzyme activity. In this review, recent evidence is summarized on the etiology and possible treatments for CD. In particular, we discuss two gene delivery systems representing recent advances in both viral and liposome technology: a novel cationic liposome-polymer-DNA (LPD) complex, DCChol/DOPE-protamine, as well as recombinant …

Beta- And Gamma-Catenin Mutations, But Not E-Cadherin Inactivation, Underlie T-Cell Factor/Lymphoid Enhancer Factor Transcriptional Deregulation In Gastric And Pancreatic Cancer., K Caca, F T Kolligs, X Ji, M Hayes, J Qian, Alan M. Yahanda Md, Facs, D L Rimm, J Costa, E R Fearon

PCI Publications and Projects

Adenomatous polyposis coli (APC) mutations are present in >70% of colon cancers. The APC protein binds to beta-catenin (beta-cat), a protein first identified because of its role in E-cadherin (E-cad) cell adhesion. In some colon cancers lacking APC defects, mutations in presumptive glycogen synthase kinase 3beta phosphorylation sites near the beta-cat NH2 terminus appear to render beta-cat resistant to regulation by APC and glycogen synthase kinase 3beta. In cells with APC or beta-cat defects, beta-cat is stabilized and, in turn, binds to and activates T-cell factor (Tcf)/lymphoid enhancer factor (Lef) transcription factors. To further explore the role of APC, beta-cat, …

Insulinlike Growth Factor 1- And 2-Augmented Collagen Gel Repair Of Facial Osseous Defects, James S. Toung, Roy C. Ogle, Raymond F. Morgan, William H. Lindsey

School of Medical Diagnostics & Translational Sciences Publications

BACKGROUND: Defects of the facial bone structure are common problems for the facial plastic surgeon. Native type 1 collagen gels (T1CGs) have been shown to mediate repair of facial critical-size defects in rat models.

OBJECTIVE: To evaluate the efficacy of T1CG augmented with insulinlike growth factor (IGF) 1, IGF-2, and a combination of IGF-1 and IGF-2 on the repair of facial critical-size defects in a rodent model.

METHODS: Twenty-four retired male breeder Sprague-Dawley rats were divided into 4 groups of 6 animals. Facial critical-size defects were created by removing the nasalis bones with a bone-cutting drill. Defects were treated with …

Induction Of Integral Membrane Pam Expression In Att-20 Cells Alters The Storage And Trafficking Of Pomc And Pc1, Giuseppe D. Ciccotosto, Martin R. Schiller, Betty A. Eipper, Richard E. Mains

Life Sciences Faculty Research

Peptidylglycine alpha-amidating monooxygenase (PAM) is an essential enzyme that catalyzes the COOH-terminal amidation of many neuroendocrine peptides. The bifunctional PAM protein contains an NH2-terminal monooxygenase (PHM) domain followed by a lyase (PAL) domain and a transmembrane domain. The cytosolic tail of PAM interacts with proteins that can affect cytoskeletal organization. A reverse tetracycline-regulated inducible expression system was used to construct an AtT-20 corticotrope cell line capable of inducible PAM-1 expression. Upon induction, cells displayed a time- and dose-dependent increase in enzyme activity, PAM mRNA, and protein. Induction of increased PAM-1 expression produced graded changes in PAM-1 metabolism. Increased expression of …

Igf Paracrine And Autocrine Interactions Between Conceptus And Oviduct., A J Watson, M E Westhusin, Q A Winger

Obstetrics & Gynaecology Publications

Development in vitro is influenced by embryo density, serum, somatic cell co-culture and the production of 'embryotrophic' paracrine and autocrine factors. Research in our laboratory has focussed principally on the insulin-like growth factor (IGF) family. We have demonstrated that pre-attachment bovine and ovine embryos express mRNAs encoding a number of growth factor ligand and receptor genes including all members of the IGF ligand and receptor family throughout this developmental interval. In addition, early embryos express mRNAs encoding IGF-binding proteins (IGFBPs) 2-5 from the one-cell to the blastocyst stage and IGFBP5 mRNA at the blastocyst stage. Cultured bovine blastocysts release up …

Trophectoderm Differentiation In The Bovine Embryo: Characterization Of A Polarized Epithelium., L C Barcroft, A Hay-Schmidt, A Caveney, E Gilfoyle, E W Overstrom, P Hyttel, A J Watson

Obstetrics & Gynaecology Publications

Blastocytst formation is dependent on the differentiation of a transporting epithelium, the trophectoderm, which is coordinated by the embryonic expression and cell adhesive properties of E-cadherin. The trophectoderm shares differentiative characteristics with all epithelial tissues, including E-cadherin-mediated cell adhesion, tight junction formation, and polarized distribution of intramembrane proteins, including the Na-K ATPase. The present study was conducted to characterize the mRNA expression and distribution of polypeptides encoding E-cadherin, beta-catenin, and the tight junction associated protein, zonula occludens protein 1, in pre-attachment bovine embryos, in vitro. Immunocytochemistry and gene specific reverse transcription--polymerase chain reaction methods were used. Transcripts for E-cadherin and …

Transient Expression Of A Translation Initiation Factor Is Conservatively Associated With Embryonic Gene Activation In Murine And Bovine Embryos., P A De Sousa, A J Watson, R M Schultz

Obstetrics & Gynaecology Publications

In the present study the abundance of mRNAs for eukaryotic translation initiation factors eIF-1A (formerly known as eIF-4C), -2alpha, -4A, -4E, and -5 was examined in in vivo-derived mouse embryos throughout preimplantation development using a semiquantitative reverse transcription-polymerase chain reaction assay. Although the mRNA profile for each gene is unique, only mRNA for eIF-1A transiently increases during embryonic gene activation (EGA) at the 2-cell stage, and this was confirmed by an independent hybridization-based assay. In in vitro-developed bovine embryos, mRNA for eIF-1A was transiently detected at the 8-cell stage, when the major activation of the genome occurs in this species. …

Na/K-Atpase-Mediated 86rb+ Uptake And Asymmetrical Trophectoderm Localization Of Alpha1 And Alpha3 Na/K-Atpase Isoforms During Bovine Preattachment Development., D H Betts, L C Barcroft, A J Watson

Obstetrics & Gynaecology Publications

This study evaluated Na/K-ATPase alpha 1- and alpha 3-subunit isoform polypeptide expression and localization during bovine preattachment development. Na/K-ATPase cation transport activity from the one-cell to blastocyst stage was also determined by measuring ouabain-sensitive 86Rb+ uptake. Both alpha1- and alpha 3-subunit polypeptides were detected by immunofluorescence to encircle the entire cell margins of each blastomere of inseminated zygotes, cleavage stage embryos, and morulae. Immunofluorescent localization of alpha1-subunit polypeptide in bovine blastocysts revealed an alpha1 immunofluorescence signal confined to the basolateral membrane margins of the trophectoderm and encircling the cell periphery of each inner cell mass (ICM) cell. In contrast, alpha …

Quantal Mechanisms Underlying Stimulation-Induced Augmentation And Potentiation, Hong Cheng

Electronic Theses and Dissertations

Repetitive stimulation of motor nerves causes an increase in the number of packets of transmitter ("quanta") that can be released in the ensuing period. This represents a type of conditioning, in which synaptic transmission may be enhanced by prior activity. Despite many studies of this phenomenon, there have been no investigations of the quantal mechanisms underlying these events, due to the rapid changes in transmitter output and the short time periods involved. To examine this problem, a method was developed in which estimates of the quantal release parameters could be obtained over very brief periods (3 s). Conventional microelectrode techniques …

The Baculovirus Anti-Apoptotic P35 Protein Promotes Transformation Of Mouse Embryo Fibroblasts., M Resnicoff, B. Valentinis, D. Herbert, D. Abraham, P D. Friesen, E. S. Alnemri, R Baserga

Department of Microbiology and Immunology Faculty Papers

The baculovirus p35 protein is a potent inhibitor of programmed cell death induced by a variety of stimuli in insects, nematodes, and mammalian cell lines. The broad ability of p35 in preventing apoptosis has led us to investigate its effect on mouse embryo fibroblasts in vitro and in vivo. For this purpose, we have used R- cells (3T3-like fibroblasts derived from mouse embryos with a targeted disruption of the insulin-like growth factor I receptor (IGF-IR) genes) and R508 cells (derived from R- and with 15 x 10(3) IGF-IRs per cell). Both cell lines grow normally in monolayer, but they do …