Cell and Developmental Biology Commons^™

Neonatal Brain: Regional Variability Of In Vivo Mr Imaging Relaxation Rates At 3.0 T-Initial Experience, L. A. Williams, N. Gelman, P. A. Picot, D. S. Lee, J. R. Ewing, V. K. Han, R. T. Thompson

Anatomy and Cell Biology Publications

PURPOSE: To retrospectively investigate regional in vivo magnetic resonance,(MR). imaging transverse and longitudinal relaxation rates at 3.0 T in neonatal brain, the p relationship between these rates, and their potential use for gray matter (G),versus-M white matter (WM) tissue discrimination. MATERIALS AND METHODS: I Informed parental consent for performance of imaging procedures was obtained in each infant. Informed consent for retrospective image analysis was not required; ethics approval was obtained from institutional review board. At 3.0 T, R1 and R2 were measured in brain regions (frontal WM, posterior WM, periventricular WM, frontal GM, posterior GM, basal ganglia, and thalamus) in …

The Ultrastructure Of The Olfactory System In Two Species Of Short-Tailed Shrews, Blarina Brevicauda And Blarina Carolinensis, Lisa Johnson Byrum

Theses and Dissertations in Biomedical Sciences

Several studies of the fine structure of the olfactory system of rodents have been conducted, but very little research has been done on members of the Insectivora. The olfactory systems of the northern short-tailed shrew, Blarina brevicauda, and the southern short-tailed shrew, Blarina carolinensis, were examined by light and electron microscopy. These shrews were live trapped in the vicinity of Norfolk, Virginia throughout all months of the year. Olfactory tissues were processed following standard transmission and scanning electron microscopy protocols. The olfactory system structures investigated included the olfactory epitheliumlmucosa (OEM), main olfactory bulb (MOB), accessory olfactory bulb (AOB), …

Endocytic Intermediates Involved With The Intracellular Trafficking Of A Fluorescent Cellular Prion Protein, Ac Magalhaes, Ja Silva, Vr Martins, Vf Prado, Ssg Ferguson, Mv Gomez, Rr Brentani, Mam Prado

Anatomy and Cell Biology Publications

We have investigated the intracellular traffic of PrPc, a glycosylphosphatidylinositol (GPI)-anchored protein implicated in spongiform encephalopathies. A fluorescent functional green fluorescent protein (GFP)-tagged version of PrPc is found at the cell surface and in intracellular compartments in SN56 cells. Confocal microscopy and organelle-specific markers suggest that the protein is found in both the Golgi and the recycling endosomal compartment. Perturbation of endocytosis with a dynamin I-K44A dominant-negative mutant altered the steady-state distribution of the GFP-PrPc, leading to the accumulation of fluorescence in unfissioned endocytic intermediates. These pre-endocytic intermediates did not seem to accumulate GFP-GPI, a minimum GPI-anchored protein, suggesting that …

Inducible Gene Expression In Cell Cultures And In Microencapsulated Cells, Yong Yu

Loma Linda University Electronic Theses, Dissertations & Projects

The mifepristone-regulated transcriptional activation system provides a means to exogenously control gene expression in transformed mammalian cells in a temporal and spatial fashion. Such a promoter activation system consists of three components: The first of these is a steroidal inducer drug, mifepristone. This drug binds to the second component, a chimeric transcription factor complex, consisting of the mutant human progesterone receptor fused to the yeast GAL4 DNA-binding domain and the Herpes simplex virus protein VP 16 activation domain. The third component is a synthetic promoter, consisting of a series of GAL4 recognition sequences upstream of the adenovirus major late E1B …

An Ultrastructural Survey Of The Nuchal Glands Of Rhabdophis Tigrinus (Serpentes: Colubridae), Kathleen A. Roberts

Biological Sciences Theses & Dissertations

Rhabdophis tigrinus, an Asian natricine snake, possesses a series of integumentary glands located in the nuchal skin. Previous studies indicated that the nuchal glands are of mesodermal origin, contain cardiac steroids analogous to bufotoxins found in the parotoid glands of toads, which are included in the snake's diet. The nuchal glands are defensive in function. Preliminary histological studies revealed differences in quality of the gland tissue compared to previous studies, and difference in fixation techniques were suspected. Seven specimens of R. tigrinus were fixed by perfusion using a conservative fixation process standard for electron microscopy. The nuchal gland series …

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

Medical Diagnostics & Translational Sciences Faculty 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 …

Efficacy Of AllowashTm Solution In Solubilization Of Bone Marrow, Alyce Marie Linthurst

Biological Sciences Theses & Dissertations

LifeNet currently cleans allograft bone utilizing Allowash^TM Technology, which encompasses the use of a closed continuous circulation chamber to remove bone marrow by flushing it with Allowash^TM Solution for a prescribed time and temperature after which, it is rinsed with various solutions to remove residual detergent that could be toxic to the recipient. A portion of this process employs Allowash^TM Solution to improve the solubilization and removal of protein and cellular elements in the red bone marrow. This study examines the effectiveness of Allowash^TM Solution in comparison to its component detergents Nonidet P40, Nonoxynol 9 and …

Pressure-Induced Intracellular Signaling In Isolated Arteries, Victor A. Miriel

Theses and Dissertations in Biomedical Sciences

The ability of cells to respond to mechanical stimuli has been studied through a variety of techniques in numerous cell types. The cells of the vascular wall have adapted to specific mechanical stresses through the activation of intracellular signaling pathways which result in cell-specific responses such as hypertrophy, hyperplasia, proliferation, and migration. Vascular smooth muscle of the arteries have been shown to be sensitive to mechanical stimuli such as stretch, and pressure.

This study attempts to add to the current knowledge of mechanotransduction by utilizing the isolated artery preparation. This preparation allows for the study of vascular smooth muscle signal …

The Role Of Glycoconjugates In Mediating Human Fertilization And Induction Of Fetomaternal Tolerance, Manish S. Patankar

Theses and Dissertations in Biomedical Sciences

Using the hemizona assay (HZA), a in vitro sperm-egg binding assay, we show that specific glycoconjugates known to inhibit immune cell interactions mediated by the selectins, potently block human sperm-egg binding. The selectin ligand sialyl Lewis^x inhibits sperm binding in the HZA by 60% at a concentration of 1 mg/ml. Our data indicates that glycodelin-A, a endometrial glycoprotein known to block sperm-egg binding in the HZA at low concentrations expresses unusual fucosylated lacdiNAc type glycans. The fucosylated lacdiNAc type sugars have been previously shown to be 15-20 fold more potent ligands of E-selectin. Glycodelin-S a seminal plasma glycoform of …

A Kinetic Investigation Of The Mechanism Of Muscle Contraction With A Series Of Nucleotides, Wei Jiang

Theses and Dissertations in Biomedical Sciences

Muscle contraction is thought to be accomplished by sliding of myosin filaments along actin filaments. Although actomyosin naturally uses ATP as an energy source, it can also use other nucleoside triphosphates (NTP) as substrates. In this work, the dependence of rate and equilibrium constants of the various steps in the muscle contraction mechanism upon nucleotide structure was investigated to unravel the dependence of the mechanical properties of the muscle upon changes in different biochemical steps of the mechanism.

The experiments measuring the dissociation of actomyosin by NTP (or mant-NTP) shows that both the rate constant of actomyosin-S1 dissociation and second …

Cellular Mechanisms Underlying Myogenic Reactivity In Isolated Arterioles, Hui Zou

Theses and Dissertations in Biomedical Sciences

The myogenic reactivity provides one of the principal mechanisms for blood flow autoregulation. The aims of the performed studies described in this dissertation were to test the role of [Ca²⁺]_i and MLC phosphorylation in arteriolar myogenic reactivity and further examine the source(s) of activator Ca²⁺ required to initiate and maintain myogenic vasoconstriction. In addition, the possible underlying mechanism of contractile protein expression was also addressed.

These studies used male Sprague Dawley rats of 200 ~ 350 grams body weight. Experiments were carried out using rat cremaster first order arterioles and mesenteric vessels. Gel electrophoresis and immunoblotting …

Microcirculation: Electrophysiological Basis For The Response Of Endothelial Cells To Inflammatory Mediators-Bradykinin, Kai Miao

Electronic Theses and Dissertations

Using conventional microelectrodes, I studied the electrical basis for determining the resting V$\sb{\rm m}$ in intact EC's from hamsters. The resting V$\sb{\rm m}$ were found to be $-$40 mV for aortic EC's and $-$43 mV for vena caval EC's. The contributions of ions to the resting V$\sb{\rm m}$ of aortic EC's were compared in terms of the transference number (t$\sb{\rm ion}$). To develop a technique for in situ monitoring changes in V$\sb{\rm m}$ of postcapillary venular EC's in the hamster mesentery, a voltage-sensitive fluorescent probe, bisoxonol, was used to load the cells and the fluorescence signals were analyzed under an …

Bcl-2 Protein Expression Is Widespread In The Developing Nervous-System And Retained In The Adult Pns, Diane E. Merry, Deborah J. Veis, William F. Hickey, Stanley J. Korsmeyer

Dartmouth Scholarship

Cell death is a common feature of neural development in all vertebrates. The bcl-2 proto-oncogene has been shown to protect a variety of cell types from programmed cell death. We have examined the distribution of bcl-2 protein in the developing and adult nervous systems. bcl-2 protein is widespread during embryonic development. Proliferating neuroepithelial cells of ventricular zones as well as the postmitotic cells of the cortical plate, cerebellum, hippocampus and spinal cord express bcl-2. Postnatally, bcl-2 is principally retained in the granule cells of the cerebellum and dentate gyrus of the hippocampus. bcl-2 expression in the CNS declines with aging. …

Changes In Intracellular Chloride During Osmotic Stress And L-Alanine Uptake In Mouse Hepatocytes, Kening Wang

Electronic Theses and Dissertations

A stable intracellular ionic environment is necessary for hepatocytes to function normally. Thus, during hypotonic shock or L-alanine uptake, hepatocytes swell and then exhibit a regulatory volume decrease (RVD), which comprises an increase in K$\sp+$ conductance (G$\sb{\rm K}$), an increased K$\sp+$ efflux, and a hyperpolarization of transmembrane potential (V$\sb{\rm m}$). Since hepatocyte intracellular Cl$\sp-$ has been demonstrated to distribute passively with V$\sb{\rm m}$, this study is designed to test the hypothesis that the hypotonic shock- or L-alanine uptake-induced hyperpolarization of V$\sb{\rm m}$ might provide an electromotive force for the efflux of hepatocyte intracellular Cl$\sp-$, which in turn would contribute osmotically …

Osteoinductivity Of Demineralized Bone: A Quantitative In Vitro Assessment, Yihong Zheng

Biological Sciences Theses & Dissertations

Acid demineralized bone (DMB) implanted in extraosseous sites induces bone formation. In vivo studies have shown that DMB stimulates the differentiation of mesenchymal cells into osteogenic cells. In this study an in vitro system was developed to demonstrate the osteoinductivity of DMB quantitatively. This in vitro working system was used to assess the osteoinductivity of variously processed DMB products as a means to evaluate their processing protocols. A human dermal fibroblastic (HDF) cell line was initiated from tissue explants as a working model, along with a human periosteal (HPO) cell line as a control. Ground DMB processed by LifeNet Transplant …

Electrophysiology, Cell Calcium, And Mechanisms Of Hepatocyte Volume Regulation, Walid E. Khalbuss

Electronic Theses and Dissertations

The electrophysiologic technique (Reuss, L., Proc. Natl. Acad. Sci. USA 82:6014, 1985) was modified to measure changes in steady-state hepatocyte volume during osmotic stress. Hepatocytes in mouse liver slices were loaded with tetramethylammonium ion (TMA$\sp{+}$) during transient exposure of cells to nystatin. Intracellular TMA$\sp{+}$ activity (a$\sp{\rm i}\sb{\rm TMA}$) was measured with TMA$\sp{+}$-sensitive, double-barreled microelectrodes. Loading hepatocytes with TMA$\sp{+}$ did not change their membrane potential (V$\sb{\rm m}$), and under steady-state conditions a$\sp{\rm i}\sb{\rm TMA}$ remained constant over 4 min in single impalements. Hyperosmotic solutions (50, 100, & 150 mM sucrose added to media) and hyposmotic solutions (sucrose in media reduced by …

Embryonic Chicken Fibroblast Collagen Binding Proteins: Distribution, Role In Substratum Adhesion, And Relationship To Integrins, Roy C. Ogle, A. Jeannette Potts, Marchall Yacoe, Charles D. Little

Medical Diagnostics & Translational Sciences Faculty Publications

Collagen binding proteins (CBP) are hydrophobic, cell surface polypeptides, isolated by collagen affinity chromatography. Antibodies to CBPs inhibit the attachment of embryonic chicken heart fibroblasts to native type I collagen fibrils in a dose-dependent manner. The CBP antibodies also induce rounding and detachment of cells adherent to a planar substratum. This process of antibody-mediated substratum detachment resulted in a clustering of CBP and cell-associated extracellular matrix at the cell surface, and the rearrangement of filamentous actin. Other functional studies showed that cells grown within a three-dimensional gel of type I collagen cannot be immunostained at the cell surface with CBP …

Effect Of Photoperiod On Developmental Morphology And Enolase Isoenzyme Immunohistochemistry In Rat And Djungarian Hamster Superficial Pineal Glands, Chalmer D. Mcclure

Loma Linda University Electronic Theses, Dissertations & Projects

The best understood functional activity of the pineal gland is its diurnal production of melatonin in response to environmental lighting cues. Several enzymes of the melatonin pathway respond to daily photoperiod changes, for example hydroxyindole-O-methyltransferase (HIOMT) and serotonin N-acetyltransferase (SNAT). Increased levels of the glycolytic enzyme neuron-specific enolase (NSE) are thought to reflect increased physiological demands placed on neurons and neuroendocrine tissues. Homodimer non-neuronal enolase isoenzyme (NNE) is immunolocalized to cells, and the hybrid enolase (consisting of subunits from NSE and NNE) has been seen in cerebellar stellate and basket cells. Although not rate limiting, concentrations of both NSE and …

Collagen Binding Proteins Derived From The Embryonic Fibroblast Cell Surface Recognize Arginine-Glycine-Aspartic Acid, Roy C. Ogle, Charles D. Little

Medical Diagnostics & Translational Sciences Faculty Publications

Several cell surface proteins (Mr = 120,000, 90,000, 63,000 and 47,000) apparently integral to embryonic fibroblast plasma membranes were extracted with detergent and isolated by collagen affinity chromatography. Certain of these proteins (Mr = 120,000, 90,000, and 47,000) were specifically eluted from collagen affinity columns by synthetic peptides containing the amino acid sequence arginyl-glycyl-aspartic acid (RGD). These data show that a number of collagen binding proteins exist on the embryonic fibroblast cell surface. Some of the proteins may be collagen receptors binding to RGD sequences in the collagen molecule while at least one of the proteins (Mr = 63,000) recognizes …

Laminin Receptors For Neurite Formation, H. K. Kleinman, Roy C. Ogle, F. B. Cannon, C. D. Little, T. M. Sweeney, L. Luckenbill-Edds

Medical Diagnostics & Translational Sciences Faculty Publications

Laminin, a basement membrane glycoprotein promotes both cell attachment and neurite outgrowth. Separate domains on laminin elicit these responses, suggesting that distinct receptors occur on the surface of cells. NG108-15 neuroblastoma-glioma cells rapidly extend long processes in the presence of laminin. We report here that 125I-labeled laminin specifically binds to these cells and to three membrane proteins of 67, 110, and 180 kDa. These proteins were isolated by affinity chromatography on laminin-Sepharose. The 67-kDa protein reacted with antibody to the previously characterized receptor for cell attachment to laminin. Antibodies to the 110-kDa and 180-kDa bands demonstrated that the 110-kDa protein …

The Effects Of Luteinizing Hormone And Adenosine 3',5'-Cyclic Monophosphate On Phospholipid Metabolism By Luteal Mitochondria, Jim John Sadighian

Chemistry & Biochemistry Theses & Dissertations

Luteinizing hormone (LH) increases intracellular concentrations of adenosine 3', 5 '-cyclic monophosphate and the phosphoinositides, phosphatidylinositol (PI), PI 4'-phosphate (PIP) and PI 4' .5 1 - bispbosphate (PIP₂). It is believed that cAMP and the phosphoinositides act concertedly to regulate mitochondrial conversion of cholesterol to pregnenolone. This study examined the effects of LH and N⁶ ,O² -dibutyryl cAMP (dbcAMP) on phospholipids metabolism by luteal mitochondria and the influence of dbcAMP and the phosphoinosi tides on mitochondrial steroid production. Mitochondria were isolated from unincubated and incubated luteal tissue by differential centrifugation. Phospholipids were extracted from the mitochondria …

The Effects Of Desoxycorticosterone, Hydrocortisone, And Prednisone On Myogenesis In Vitro, Gregory K. Nienaber

Masters Theses

In order to obtain proper muscle development in tissue culture, certain conditions must prevail. There is a delicate balance of factors, and elimination of even one of these factors leads to poor and improper development. Muscle cells grown in the absence of fibroblasts usually fail to differentiate. Therefore, proper development depends upon the presence of two cell types: myoblasts and fibroblasts. Investigators have demonstrated that the fibroblasts are necessary in that they produce collagen which is necessary for proper muscle development. The present study has shown that desoxycorticosterone, hydrocortisone, and prednisone at concentrations of 10, 1, and 0.1 ug/ml of …

A Study Of Regeneration Of Peripheral Nerve In The Rat, James C. Jay

Loma Linda University Electronic Theses, Dissertations & Projects

Due to improvements in fixation and embedding techniques a restudy of regenerating peripheral nerve was thought advisable in order to better understand and describe the processes which take place.

Femoral nerves of white Wistar rats were used. The lesions were made by either crushing or severing the nerve. After a period of regeneration, varying from 12 hours to six days, the wound was reopened and the injured portion fixed in situ with 1% osmium tetroxide. The tissues were then removed, dehydrated, embedded and sectioned. The sections were stained and studied with a modified RCA EMU2A electron microscope.

Observations revealed that …

White Muscle Disease Of Sheep : Symptoms And Pathology, M R. Gardiner

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

WHITE Muscle Disease (WMD) was recognised for the first time in Western Australian sheep during the winter of 1960.

The first outbreak occurred on a property in the South Stirling district in the middle of July and this was followed by outbreaks in August, September and early October, at Mayanup, Kendenup, Mt. Barker, Duranillin, Kojonup, South Stirling and Pinjarra.