Life Sciences Commons^™

Cytoskeletal Changes During Radiation-Induced Neoplastic Transformation Of Human Prostate Epithelial Cells, S. C. Prasad, P. J. Thraves, J. S. Rhim, M. R. Kuettel

Scanning Microscopy

We recently reported tumorigenic transformation of SV 40-immortalized neonatal human prostate epithelial cells (267Bl) by exposure to fractionated doses of X-rays. Altered morphology and anchorage independence were observed following two successive fractions of 2 Gy each (F3-SAC). Additional 2 Gy treatments to these non-tumorigenic cells to a total dose of 30 Gy resulted in radiation-transformed tumorigenic colonies (267Bl-SXR). Malignant transformation of parental 267B 1 cells was also achieved by consecutive 2 Gy exposures to a total dose of 30 Gy (267Bl-XR). This study discusses the cytoskeletal changes in the F3-SAC, 267Bl-XR and 267Bl-SXR derivatives of these human prostate epithelial cells. …

Pre-Embedding Staining Of Single Muscle Fibers For Light And Electron Microscopy Studies Of Subcellular Organization, Evelyn Ralston, Thorkil Ploug

Scanning Microscopy

Skeletal muscle fibers are large, multinucleated cells which pose a challenge to the morphologist. In the course of studies of the distribution of the glucose transporter GLUT4, in muscle, we have compared different preparative procedures, for both light (LM) and electron microscopy (EM) immunocytochemistry. Here we show that pre-embedding staining of single teased fibers, or of single enzymatically dissociated fibers, has several advantages over the use of sections for observing discrete patterns that extend over long distances in the cells. We report on an optimization study carried out to establish fixation and permeabilization conditions for EM immunogold labeling of the …

Structural And Calcification Patterns Of The Neonatal Line In The Enamel Of Human Deciduous Teeth, Tetsuo Kodaka, Tsuneyoshi Sano, Shohei Higashi

Scanning Microscopy

The neonatal line of the enamel in human deciduous teeth was observed by scanning electron microscopy using secondary and backscattered electron signals. The neonatal line containing irregular structures of enamel prisms with disordered crystal arrangements was basically formed by the abrupt bending of the prisms towards the root. Usually, the prisms gradually bent back again to regain their previous orientation, but the prisms in the inner and the surface layer sometimes ran straight ahead after bending. The prism sheath regions showing hypocalcification contained a relatively large amount of organic material as shown by treatment with chromium sulfate. When etched with …

Monte Carlo Simulation Of Secondary Electron Emission From Thin Film/Substrate Targets, K. Murata, M. Yasuda, H. Kawata

Scanning Microscopy

We have developed a Monte Carlo simulation model of secondary electron emission from thin film/substrate samples, taking into consideration their exact boundary condition. First, the validity of the model is checked in comparison with the experimental data reported such as the secondary electron emission and backscattering yields from thick Al, thick Au targets and Al thin films on a Au substrate, the energy distribution of secondary electrons, and the contribution of backscattering to the secondary electron emission yield. The agreement is relatively good. Next, we have applied the model to the secondary electron emission from Au films on an Al …

Generation Of High Efficiency Ssdna Hybridization Probes By Linear Polymerase Chain Reaction (Lpcr), Gregory W. Konat

Scanning Microscopy

The polymerase chain reaction (PCR) methodology can be employed to produce DNA hybridization probes. The major advantages of this paradigm over other techniques include superior specific activity of the probes, the versatility of sequence selection, the ability to produce short probes, and the simplicity of the procedure. We have further improved the efficiency of PCR probes by generating single stranded (ssDNA) probes that do not reanneal with themselves in solution, and hence, their availability for the interaction with the complementary sequences of the target is profoundly increased. Protocols for ³²P-dCTP labeled and digoxigenin-dUTP labeled probes have been elaborated to …

Louisiana Agriculture Magazine, Summer 1996, Lsu Agricultural Experiment Station

Louisiana Agriculture

No abstract provided.

Microhardness And Scanning Electron Microscopy Analysis Of Nd:Yag Laser And Acid Treatment Effects In Dentin, J. M. White, G. L. Adams

Scanning Microscopy

Laser irradiation at and above parameters producing the modification threshold for dentin causes structural changes to the dentin surface. This study determined the microhardness of dentin before and after laser modification and acid treatment using a repeated-measures de-sign. Seven dentin sections (4 mm in thickness) were cut from freshly extracted non-carious third molars using a diamond saw. The middle occlusal third was used as the test dentin surface. One section served as a control (C); three received laser modification (L) and then acid treatment (L + A); and three received acid (A) and then laser treatment (A + L). Laser …

Experimental Nephrolithiasis In Rats: The Effect Of Ethylene Glycol And Vitamin D3 On The Induction Of Renal Calcium Oxalate Crystals, R. De Water, E. R. Boevé, P. P. M. C. Van Miert, G. Deng, L. C. Cao, Th. Stijnen, W. C. De Bruijn, F. H. Schröder

Scanning Microscopy

Using ethylene glycol (EG) and vitamin D3 as crystal-inducing diet (CID) in rats, we investigated the effect of the dosage of EG on the generation of chronic calcium oxalate (CaOx) nephrolithiasis. We collected weekly 24 hour urines and measured herein the amount of oxalate, calcium, glycosaminoglycans (GAG's), creatinine, protein, alkaline phosphatase (AP), 𝝲-glutamyl transpeptidase (𝝲GT), and N-acetyl-𝝱-glucosaminidase (NAG). The potential of these urines to inhibit crystal growth and agglomeration was also evaluated. After four weeks, the kidneys were screened by histology and radiography for the presence of CaOx crystals and the amount of kidney-associated oxalate was biochemically measured. Using 0.5 …

Problems In Preparation Of Chromosomes For Scanning Electron Microscopy To Reveal Morphology And To Permit Immunocytochemistry Of Sensitive Antigens, A. T. Sumner

Scanning Microscopy

Although much information about chromosome structure and behaviour has been obtained using light microscopy, greater resolution is needed for a thorough understanding of chromosome organisation. Scanning electron microscopy (SEM) can provide valuable data about these three-dimensional organelles. The introduction of methods using osmium impregnation of methanol-acetic acid-fixed chromosome spreads revolutionised matters, producing life-like images of chromosomes. Nevertheless, it became clear that osmium impregnation introduced various artefacts, although the resulting images were still useful. Methanol-acetic acid-fixed chromosomes are, in fact, flattened on the glass substratum, and the 3-dimensional appearance obtained after osmium impregnation is the result of swelling during this process. …

Preparation Of Plasmid Dna In Transfection Complexes For Fluorescence And Electron Spectroscopic Imaging, Marek Malecki

Scanning Microscopy

The aim of this project was to develop procedures necessary to study mechanisms of receptor mediated gene transfer by means of integrated microscopy.

Plasmid DNA was incorporated into a transfection complex consisting of poly(L)lysine and transferrin to which the nuclear localization signal was conjugated. This complex was presented to cultured glioma cells. Preparation of the transfected DNA for imaging was pursued by two methods. In the first method tetramethylrhodamine, nanogold, and ferritin were linked through streptavidin to the biotinylated plasmid DNA. Trafficking of the fluorescent derivatives was studied in living cells with fluorescence microscopy. Then, selected cells were rapidly cryo-immobilized. …

Common Epidermal Lesions Of The Bowhead Whale, Balaena Mysticetus, William G. Henk, Dianna L. Mullan

Scanning Microscopy

Samples of common skin abnormalities from 23 subsistence-harvested bowhead whales (Balaena mysticetus) were examined. Most lesions fell into three broad classes: shallow lacerations, circular depressions, and epidermal sloughing. Both circular depression lesions and epidermal sloughing lesions may be divided into more than one subgroup based on morphological criteria. Examination of each of the subgroups using light and scanning electron microscopy suggests relationships among the subgroups of a class. These proposed relationships are discussed, as are some possible etiologies. Scanning electron microscopy reveals abundant bacteria and diatoms present in association with each lesion class but no evidence of a particular association …

Adhesion And Endocytosis Of Calcium Oxalate Crystals On Renal Tubular Cells, Y. Kohjimoto, S. Ebisuno, M. Tamura, T. Ohkawa

Scanning Microscopy

The present investigation was designed to study interactions between Madin-Darby canine kidney (MOCK) cells and calcium oxalate monohydrate (COM) crystals and to clarify the significance of these crystal-cell interactions in stone pathogenesis.

MOCK cells cultured in the presence of COM crystals showed a time-dependent uptake of crystals; this was specific for COM crystals. In the dynamic model system designed to study these phenomena under more physiological conditions, COM crystals adhered to the cell surface and were subsequently internalized. In this endocytotic process, the microvilli of the cell appeared to play an important role. The observation by scanning electron microscopy of …

X-Ray Microscopy: Preparations For Studies Of Frozen Hydrated Specimens, A. Osanna, C. Jacobsen, A. Kalinovsky, J. Kirz, J. Maser, S. Wang

Scanning Microscopy

X-ray microscopes provide higher resolution than visible light microscopes. Wet, biological materials with a water thickness of up to about 10 μm can be imaged with good contrast using soft X-rays with wavelengths between the oxygen and carbon absorption edges (at 24 and 43 Å). The Stony Brook group has developed and operates a scanning transmission X-ray microscope (STXM) at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory. The microscope is used for imaging with a current resolution of 50 nm, and for elemental and chemical state mapping.

Radiation damage imposes a significant limitation upon high resolution X-ray …

Promoting And Managing Genome Innovation, Suzanne A. Sprunger, Gianna Julian-Arnold

RISK: Health, Safety & Environment (1990-2002)

An introduction to the symposium, Promoting and Managing Genome Innovation held October 1995. The conference was organized by Professor Thomas G. Field, Jr. and Gianna Julian-Arnold. The conference was funded in part by the Ethical, Legal and Social Issues component of the D.O.E. Human Genome Program; Nixon, Hargrave, Devans & Doyle L.L.P., Rochester, N.Y.; and Human Genome Sciences.

Genome Research And Traditional Intellectual Property Protection -- A Bad Fit?, Kate H. Murashige

RISK: Health, Safety & Environment (1990-2002)

Dr. Murashige addresses the need for a patent system more closely tailored to the needs of biotechnology. For example, the obviousness requirement may interfere with using patents to recoup high costs of work when it could arguably be done by researchers of ordinary skill.

Impact Of The Human Genome Project At The Interface Between Patent And Fda Laws, Brian C. Cunningham

RISK: Health, Safety & Environment (1990-2002)

Mr. Cunningham stresses the broad scope of biotechnological innovations. Besides endorsing the need for a new oversight commission to deal with potential social issues, he suggests, for example, that some products should be treated like biologics rather than new drugs.

Social Issues Of Genome Innovation And Intellectual Property, Elaine Alma Draper

RISK: Health, Safety & Environment (1990-2002)

Dr. Draper's focus is the use of personal information derived from genome research. She identifies several potential problems, including access to and control of genetic information, employment discrimination and social stratification. She also recommends possible solutions.

Table Of Contents Volume Seven, Number Three, Summer 1996, Risk Editorial Board

RISK: Health, Safety & Environment (1990-2002)

Table of contents for the journal RISK: Health, Safety & Environment (ISSN: 1073-8673)

Development Of Vaccines To Meet Public Health Needs: Incentives And Obstacles, Phillip K. Russell

RISK: Health, Safety & Environment (1990-2002)

Dr. Russell explains how such matters as high 'costs of regulation, lack of an effective plan for delivery (particularly abroad) and politics can interfere with providing globally needed vaccines.

Low Calcium Diet In Hypercalciuric Calcium Nephrolithiasis: First Do No Harm, Bernhard Hess

Scanning Microscopy

Many studies indicate that up-regulated production of 1,25(OH)2-vitamin D3 (calcitriol) with increased intestinal absorption of calcium is the primary event causing idiopathic hypercalciuria. Thus, a low calcium diet appears to be a straightforward strategy in calcium stone formers with hypercalciuria (HCSF). However, the efficacy of such a regimen has never been established, and lowering calcium intake from 1000 to 400 mg/day further enhances calcitriol production. On a diet chronically restricted in calcium, many stone formers increase their intake of animal flesh protein. The latter is known to increase renal mass, and calcitriol levels indeed are positively correlated with renal mass …

The Appearance Of Endothelium In Small Arteries After Treatment With 5-Fluorouracil. An Electron Microscopic Study Of Late Effects In Rabbits, M. Cwikiel, J. Eskilsson, J. B. Wieslander, U. Stjernquist, M. Albertsson

Scanning Microscopy

Cardiotoxicity is an unexplained toxic manifestation of 5-fluorouracil (5-FU). Its possible mechanism could be a direct cytotoxic effect on the vascular endothelium. We have tested this hypothesis in an experimental study in rabbits, using scanning and transmission electron microscopic evaluation of endothelium in small arteries (the central artery of the ear). The perfusion fixation method at physiological pressure and temperature was used. Both local and systemic effects of 5-FU on endothelium were studied 1, 3, 7, 14 and 30 days after in vivo treatment with 5-FU. Fifteen rabbits were used and five additional animals served as controls. The following parameters …

Impact Of The Incubation Medium On The Endothelium Of Autologous Vein Grafts: Damage Scoring By Scanning Electron Microscopy, M. A. Konerding, M. Knocks, H. -R. Zerkowski

Scanning Microscopy

The aim of this study was to examine the influence of different incubation media on the morphology of the endothelium of great saphenous vein grafts and establish a suitable scoring system for the evaluation of damage caused by these media. Fifty specimens of saphenous veins from ten patients during elective aorto-coronary bypass surgery were used. Ten specimens served as controls; the others were assigned to test groups and exposed to heparinized whole blood, Bretschneider's HTK, human albumin or Ringer's solution. Specimens exposed to heparinized blood showed only slight morphological alterations, whereas the other three mediums caused severe damage. Thus, heparinized …

Spiral Structures In The Wall Of The Hepatic Venous System In The Dog, Shigenori Okada, Yoshikuni Ohta

Scanning Microscopy

Unique spiral structures, located in the wall of the hepatic venous system in the dog, were examined in the central veins and the hepatic venous branches, utilizing microvascular corrosion casting and freeze-fracture technique in scanning electron microscopy and transmission electron microscopy of tissue sections. The whole hepatic venous system was divided into 4 portions: the central, sublobular, collecting and branches of the hepatic veins. The central vein was spindle-shaped with several compressions. Removing the endothelial cells of the central vein, pathways of venous sinusoids were like a labyrinth. In the sublobular veins, spiral structures distinctly appeared as the diameter increased. …

Microprobe Analysis Of Element Distribution In Rabbit And Dog Erythrocytes As Examples Of "High" And "Low" Potassium Cells, H. R. Catchpole, M. B. Engel

Scanning Microscopy

The concentrations of Na, Mg, P, S, Cl, K and Fe were determined by microprobe in near 100% hematocrit suspensions of rabbit and dog erythrocytes prepared by freezing and drying. These cells are representative, respectively, of "high" potassium, "low" sodium, and "high" sodium, "low" potassium cells. Water contents of the cells were the same, as were, approximately, the levels of Cl, S and Fe. Rabbit P was nearly double that of the dog. For the rabbit, the cell Na/K ratio was 0.21 and for the dog 15.4, illustrating the major diffusible electrolyte difference between these two types of cell. The …

Apoptosis And Red Blood Cell Echinocytosis: Common Features, Alexei B. Chukhlovin

Scanning Microscopy

Apoptosis of nucleated blood cells induced by oxidants and/or reactive oxygen species is accompanied by the typical membrane pathology. Meanwhile, red blood cell (RBC) membrane. is a popular object for studying appropriate cytotoxic effects. Scanning electron microscopy provides a reliable tool for detecting the oxidative changes in RBC shape and size. Transition of normal discoid erythrocytes to crenated forms (echinocytes) is often induced by the same factors which cause apoptosis of blood cells, e.g., ionizing radiation and other reactive oxygen intermediate-inducing agents, exogenous oxidants, in vitro aging conditions, cytosolic calcium increase, etc. Moreover, the biochemical membrane alterations in oxidant-induced echinocytosis …

Pathological And Immunocytochemical Changes In Chronic Calcium Oxalate Nephrolithiasis In The Rat, R. De Water, E. R. Boeve, P. P. M. C. Van Miert, C. P. Vermaire, P. R. W. A. Van Run, L. C. Cao, W. C. De Bruijn, F. H. Schroder

Scanning Microscopy

In the present study, we exposed rats to a crystal-inducing diet (CID) consisting of vitamin D3 and 0.5% ethylene glycol (EG), and we investigated histologically the kidney damage induced by the deposition of calcium oxalate (CaOx) crystals. After 28 days, 50 % of the animals had renal CaOx crystals, of which 60% also had small papillary stones. Most crystals were present in the cortex. The occurrence of these crystals coincided with morphological and cytochemical changes: glomerular damage, tubular dilatation and necrosis, and an enlargement of the interstitium. The number of epithelial and interstitial cells positive for the proliferating cell nuclear …

Touch-Plate And Statolith Formation In Graviceptors Of Ephyrae Which Developed While Weightless In Space, Dorothy B. Spangenberg, Elisa Coccaro, Russell Schwarte, Brian Lowe

Scanning Microscopy

Ultrastructural studies of the statocysts and touch-plates of graviceptors (rhopalia) of Aurelia ephyrae revealed that (1) touch-plate hair cells are present; and (2) cytoplasmic strands from the hair cell bases extend from the neurite plexus to touch similar strands from the lithocytes. This close association of hair cell neurites and statocysts may have important implications regarding the transmitting and processing of positional information with respect to the gravity vector.

Graviceptors of ephyrae which developed while weightless in microgravity were compared with controls at the ultrastructural level. We found that hair cells of ephyrae which developed in microgravity had fewer lipid …

Ion Beam Induced Charge Microscopy Of Integrated Circuits, M. B. H. Breese

Scanning Microscopy

The ion beam induced charge (IBIC) microscopy technique has recently been developed as a means of imaging the depletion regions of working microelectronic devices beneath their thick metallisation and passivation layers. IBIC microscopy is analogous to electron beam induced current microscopy but has the advantages of a larger analytical depth, lower lateral scattering of the incident focused MeV ion beam and negligible charging effects. These characteristics enable IBIC to image small, buried active device regions without the need to remove the surface layers prior to analysis. The basis of this new technique is outlined and the applications for integrated circuit …

Lectin-Cytochemistry Of Experimental Rat Nephrolithiasis, W. C. De Bruijn, R. De Water, E. R. Boeve, P. R. W. A. Van Run, P. J. Vermaire, P. P. M. C. Van Miert, J. C. Romijn, C. F. Verkoelen, L. C. Cao, F. H. Schroder

Scanning Microscopy

Lectin reactivity in epithelial apical cell coats of normal rat kidneys was compared to that from animals subjected to crystal inducing diets (CID). The aim was to see whether the absence of lectin reactivity in cell coats is related to intratubular calcium oxalate crystal retention. In normal rat kidneys, after a pre-embedding procedure, it was observed that at the ultrastructural level, reactivity was present but that the lectin specificity for the various parts of the nephron might have to be reconsidered. There was heterogeneity between the epithelial cells with respect to the presence of coat material in the tubular cell …

Atomic Force Microscopy Of Dna, Nucleoproteins And Cellular Complexes: The Use Of Functionalized Substrates, Yuri L. Lyubchenko, Robert E. Blankenship, Alexander A. Gall, S. M. Lindsay, Ottavio Thiemann, Larry Simpson, Luda S. Shlyakhtenko

Scanning Microscopy

Progress towards rapid and simple characterization of biomolecular samples by scanning probe microscopy is impeded mainly by limitations of the current approach to sample preparation. We are working on approaches based on chemical functionalization of mica. Treatment of mica with aminopropyltriethoxy silane (APTES) makes the surface positively charged (AP-mica) and able to hold DNA in place for imaging, even in water. We have shown that AP-mica is an appropriate substrate for numerous nucleoprotein complexes as well. The AFM images of the complex of DNA with RecA protein are stable and indicate a structural periodicity for this filament. AP-mica holds strongly …