bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of Ultrastructural Morphology of Tissue fixed in Formalin and Prefer™
Authors: Billings Steven D , Goheen Michael P 
Published: July 2020

Abstract
Ultrastructural examination is sometimes necessary for diagnosis of surgical pathology material. Not uncommonly, tissue is not fixed in 3% glutaraldehyde prior to realizing that electron microscopy would be valuable or even necessary to render a diagnosis. It is well known that formalin can be an adequate fixative for ultrastructural evaluation of tissue. Increasingly, non-formalin based fixatives have become more popular with routine surgical pathology practice. Prefer™, a glyoxal-based fixative, has become a popular substitute for formalin in many institutions. We are not aware of any study that has compared ultrastructural morphology of tissue fixed in formalin to tissue fixed in a glyoxal-based fixative.
To address this question, we took sections of fresh tissue from three different tumors (metastatic melanoma involving a lymph node, squamous cell carcinoma of the lung, and mixed papillary serous and clear cell carcinoma of the ovary) and fixed a portion of each in 3% glutaraldehyde, 10% neutral buffered formalin, and Prefer™.
Skeletal Muscle Ultrastructural Alterations In Alcoholism
Authors: Müller B , Finol HJ , Montes de Oca I , Mayorca. A 
Published: July 2020

Abstract
Two forms of muscular alterations have been described in alcoholic patients, one acute, the so called Hypokalemic alcoholic Myopathy; focal or diffuse pain, swelling, tenderness and weakness of skeletal muscle are the main clinical features, and the chronic one with proximal muscle weakness wich progresses slowly in a period of weeks or months Ultrastructurally myofibril disorganization and necrosis where described.
In this work we present a systematic study of skeletal muscle alterations in four alcoholic patients who attended the Department of Internal Medicine at Caracas University Hospital. The patients were males, ages between 56 and 62 years old, and presented chronic alcoholism with muscle weakness with a more distal distribution and polymyalgia. Biopsies were taken from quadriceps femorismuscle with a percutaneous neddle and processed for routine transmission electron microscopy.
Muscle fibers showed different degrees of atrophy with myofibril disorganization (Fig.l) and disappearence (Fig.2). Myonuclei were hyperchromatic and intermyofibrilar spaces were widened and exhibited abundant lipid droplets.
Kidney Ultrastructural Pathology In Plasmodium Berghei Murine Malaria: Tubular Cell and Peritubular Capdllary Alterations
Authors: Pulido-Méndez M , Finol HJ , Rodríguez-Acosta A , Márquez A , González N , Andrade G , Boada-Sucre A 
Published: July 2020

Abstract
Renal function impairment can be found in severe or complicated P. falciparum malaria. Some studies report 2-5% incidence of acute renal failure associated with high mortality (1). Causes of acute renal damage are not clearly understood but massive hemoglobinuria seems unlikely in the majority of cases and different immunopathogenic mechanisms leading to tubulointerstitial nephritis are currently proposed (2). Ultrastructure of renal lesions in malaria have been performed in humans (3) and in some infections of rodents and monkeys (4). These studies report abnormalities mainly in the glomerular area and references to tubular cell pathologic changes are still limited. This work describes tubular and capillary alterations in P. berghei malaria.
P. berghei parasitized erythrocytes (strain from the Swiss Tropical Medicine Institute) were inoculated intraperitoneally in C57BL/6 male mice. Renal samples were obtained at 13th-14th days post-infection when severe illness was evident and parasitaemia reached 40-50%. Samples were processed by routine techniques for transmission electron microscopy and observed in Hitachi H-500 and H-7100 electron microscopes.
Successful Management of Infectious Pathogens From Microbial Outbreak Specimens: Safety and Identification
Authors: Humphrey Charles D 
Published: July 2020

Abstract
Despite significant advances in molecular biology and immunology, electron microscopy (EM) continues to be useful for morphologic identification of infectious microbes in body fluid and cultured specimens from humans and experimental animals. Morphologic identification using negative stain and/or thin-section EM is often a primary tool in public health investigations, followed by immunologic, molecular, or cultured isolation. Difficulties encountered are usually related to the length of time between specimen (e.g. stool) collection and preparation for EM and/or handling and shipping conditions. Another negative mitigating factor may be multi-lab interventions prior to arrival. Appropriate specimen collection, storage, and handling prior to attempts to identify the agent are important factors for successful identification.
Barrier-control guidelines called “Universal Precautions for Laboratories“ have for many years been recommended by U.S. and international health services organizations. The guidelines are based on the premise that safe work sites result from a combination of engineering controls, management policies, work practices, and, when required, prompt medical intervention.
Vascular Regression In Gill Filters of Tadpoles of Xenopus Laevis Daudin: A Qualitative and Quantitative Sem Study on Vascular Corrosion Casts
Authors: H. Bartel  , B. Minnich  , I. Margreiter  , A. Lametschwandtner  
Published: July 2020

Abstract
During metamorphosis amphibian tadpoles regress gills, tail and other larval structures. Thus gills are a good model to study how a highly complex three-dimensional vascular network regresses and finally disappears. Presently, only the microvascularization of external gills of larvae of Hynobius dunni(2) and Litoria ewingi(3) is examined. The present study analyzes the spatio-temporal changes which the gill 3D-vascular network undergoes during metamorphosis using SEM of microvascular corrosion castings and a newly developed 3D-morphometry system (4, 5).
Vascular casts of gills of tadpoles of the South African Clawed Toad, Xenopus laevis Daudin of stages 57 to 62 (6) were analyzed by SEM. Stereopaired images (tilting angle: 6 degrees) grabbed with a slow scan frame grabber (Orion 4.27) from the SEMs photo-display were imported into a 3Dmorphometry system (6) to measure vessel diameters, interbranching distances, branching angles and branching orders of filter row venules. This study reports the changes in the branching orders only.
Physiological Aspects of Vascular Corrosion Casting
Authors: Olson KR 
Published: July 2020

Abstract
Vascular corrosion replicas provide unique three-dimensional models of both macro- and microcirculatory angio-architecture. In most replication procedures, blood is initially flushed from the vasculature with a low viscosity, non-clotting medium, such as saline, prior to infusion with the unpolymerized resin. While this removes cellular elements from the vessels and prevents coagulation, the chemical characteristics of the saline and the mode in which it is infused can potentially affect vascular smooth muscle. This can be disadvantageous if subsequent distribution of the resin does not faithfully mimic normal perfusion pathways, or if the vascular lumen is either narrowed due to vasospasm or distended due to excessive intravascular pressure. Alternatively, the composition of the saline can be modified to enhance the replication process. This may be done merely to ensure complete filling of the vasculature or to evaluate anatomical foci instrumental in physiological and pharmacological regulation of perfusion distribution.
Exact Detection of Arterial and Portal Branches of the Terminal Afferent Vessels in the Rat Liver By Means of Corrosion Casts and Edx
Authors: Spornitz Udo M , Bartuskova Irena , Morson Gianni 
Published: July 2020

Abstract
The physiological necessity of the dual afferent blood supply of the liver and the morphological features of the macrocirculation are well understood. The microcirculation, however, still poses a number of unsolved questions. In particular the nature of the terminal junctions of the arterial and portal blood stream with the sinusoids has so far not been satisfactorily elucidated (1-2). Scanning electron microscopy alone or in combination with corrosion casts cannot solve the problem, because it remains difficult to tell the different vessels apart. Under favorable circumstances the terminal portal vein is the easiest to be distinguished with corrosion casts. This is due to the fact that its relatively wide branches surround the classical liver lobules along the major parts of their circumference. The diameter of the terminal hepatic artery is in its initial segments not as wide as the initial segments of the terminal portal vein.
Angioarchitecture of Palatine Mucosa of Young Rabbits : A Sem Study of Vascular Corrosion Casts
Authors: Kronka Marcia C , Watanabe Ii-Sei 
Published: July 2020

Abstract
The angioarchitecture of the hard palate mucosae of young rabbits was investigated by using microvascular casting of low density resin (Mercox®). The injected specimens were examined by scanning electron microscope (SEM). The palatine mucosa and the adjacent gingiva have an important function during the mastication, vocalization and swallowing. The purpose of this paper is to analyse the structure of the micro vasculature of the palatine mucosa.
The animals were anesthetized and perfused with approximately 500ml of prewarmed (37°C) heparinized saline. Then, 30-40ml of Mercox® CL2-B, prepared conforming the manufacterer's intructions, were carefully injected via aorta artery under manual pressure. After the complete resin polymerization, specimens were dissected and macerated with 10% NaOH for several days at room temperature. The vascular casts were rinsed in distelled water, dried, mounted in stubs, coated with gold and examined in JEOL 6100 scanning electron microscope.
Triggered Morphology Generation in a Biosynthetic Model Spider Dragline Silk Protein
Authors: Valluzzi R , Szela S , Kirschner D , Kaplan D 
Published: July 2020

Abstract
Recombinant DNA techniques were used to prepare a protein modeled after the consensus sequence of Nephila clavipesspider dragline silk, incorporating methionine residues to serve as redox “triggers”. In addition a water-soluble 27 residue peptide model of the dragline silk consensus amorphous sequence, representing a single amorphous block in the protein sequence, was prepared and characterized to gain additional insight into the behavior of the amorphous phase. X-ray diffraction, electron diffraction, transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FTIR) were used to characterize the ability of the recombinant protein to form (β-sheet crystals and the effect of the oxidation state of the redox trigger on crystallinity and noncrystalline order in the sample. The formation of intractable β-sheet crystallites is a major cause of insolubility in proteins that can form this type of secondary structure. Changes in crystallinity were observed when triggered/reduced (insoluble) and untriggered/oxidized (soluble) protein samples were compared.
Strategies For Immunodissection Of The Connective Tissue Matrix And Basement Membranes
Authors: Keene Douglas R , Tufa Sara F 
Published: July 2020

Abstract
Connective tissue matrices are quite diversified and include that composing skin, tendon, bone, cartilage, cornea and many others. The main component of the connective tissue matrix is collagen, composing approximately 70% of the dry weight of the human body. More members of the collagen family are discovered each year, with over twenty types described to date. Many of these collagens are tissue specific. In addition to the collagens, the connective tissue matrix is also the residence of epithelial and endothelial basement membranes and many other molecules including a variety of proteoglycans and elastic fiber components. The cells within the matrix are highly differentiated and task specific.
Using immunocytochemical technique applied at the level of the electron microscope, we have focused our resources to understand the structure and functional role of these matrix molecules.
Live Tissue Video-Microscopy Of Different Vascular Beds In The Eye: A Microcosmosm Of Untouched Microcirculation
Authors: Becker Matthias D , Martin Tammy M , Planck Stephen R , Rosenbaum J T 
Published: July 2020

Abstract
The eye offers the unique possibility of direct visualization of microvessels in readily accessible tissues. Due to the compact anatomy of the eye, different microvascular beds of different embryological origin can be examined in albino mice without traumatic tissue preparation, Epifluorescence microscopy in combination with different fluorescent dyes has been applied. To observe individual cells in vessels, rhodamine 6G can be used to stain leukocytes and platelets, and acridine orange stains nuclei of leukocytes and endothelial cells. Fluorescein-isothiocyanate (FITC)-dextran labels plasma.
Iris, limbus, conjunctival and choroidal vessels under normal and inflammatory conditions (endotoxin-induced uveitis) were examined in BALB/c mice and Lewis rats. Digital video technology can be applied to intravital microscopy with great benefit: video quality remains on a high level and the amount of time for the quantification procedure and the need of expensive software is reduced compared to classical video recording.
Astrosclereids In Needles Of Old-Growth Douglas-Fir Trees
Authors: Apple M , Soeldner A , Hamill R , Tiekotfer K 
Published: July 2020

Abstract
Old-growth Douglas-fir trees in the Pacific Northwest are venerable giants that often live for 500 years and reach heights of over 75 meters. Their needles are relatively ephemeral and small but have the important role of interacting with the atmosphere in order to transpire and photosynthesize. Within the photosynthetic mesophyll tissue of Douglas-fir needles, there are large, non-living cells with lignified secondary cell walls that are known as astrosclereids. Apparent channels in the secondary wall may provide a route for exchange or transport of materials between the astrosclereid lumen and mesophyll cells or the vascular cylinder. Astrosclereids may be involvev d in storage of secondary metabolites such as tannin and may develop in response to fungi, mistletoe, or other pathogens. More knowledge is needed about the development, structure and function of astrosclereids.
Needles were collected from sapling and old-growth Douglas-fir, Pseudotsuga menziesii, (Mirb.) Franco, trees at the Wind River Canopy Crane in Carson, Washington and from three sites in the Cascade Mountains of Oregon in 1997 and 1998.
Visualization Of The Transcription Factor Agl15 In Plant Embryos: A Case Of Regulation Via Cellular Localization
Authors: Fernandez DE , Perry SE , Lehti MD 
Published: July 2020

Abstract
AGL15 (AGAMOUS-like 15) was originally identified as a sequence preferentially expressed in developing plant embryos by comparing PCR-generated ‘differential displays’ of embryo and non-embryo RNA populations. The sequence is expressed at low levels and encodes a member of the MADS domain family (named for the first four members to be identified: MCM1, AGAMOUS, DEFICIENS, and SERUM RESPONSE FACTOR) of regulatory factors. Members of the MADS domain family play pivotal roles in critical developmental events in a wide variety of organisms: in specification of mating type in yeast (MCM1), in responses to the environment in human cells (SRF), in control of mesoderm differentiation in Drosophila and muscle differentiation in humans (MEF2), and in determination of meristem and organ identity during flower development in plants (AGAMOUS, DEFICIENS/APETALA3, GLOBOSA/PISTILLATA, etc.). AGL15 is the only MADS domain factor identified to date that is expressed in a highly preferential manner in plant embryos.
Morphological And Immunocytochemical Analysis Of Polyhydroxybuterate Distribution In Transgenic Plants
Authors: Colburn SM , Biest N , Hao M , Houmiel K , Mitsky T , Padgette S , Reiser S , Slater S , Tran M , Valentine H , Gruys K 
Published: July 2020

Abstract
Poly-β-hydroxybuterate (PHB), a biodegradable polyester, is accumulated as a storage compound in many species of bacteria. It belongs to a class of polymers called polyhydroxyalkanoates (PHAs). PHA's were originally identified in 1923.However these polymers first came to the attention of industry in the early 1980's when they were recognized as having thermoplastic properties.Monsanto currently markets a form of PHA produced via fermentation under the trade name Biopol™. It is used to make biodegradable plastic products such as credit cards, bottles and disposable drinking cups. However fermentation is an expensive route to production. The use of crop plants genetically engineered to produce PHA's could provide a less expensive source of the plastic and therefore a more attractive alternative to traditional non-biodegradable petrochemical derived plastics. PHB production in plants was first demonstrated in 1992 in transgenic Arabidopsis thaliana by Chris Somerville and coworkers. They showed that PHB production was tolerated by the plant if it was targeted to the chloroplasts.
Chloroplast Ultrastructure And Absorption Properties Of The Alga Phaeocystis Antarctica Karsten: A Qualitative Study Using Electron Tomography
Authors: Moisan Tiffany A , Ellisman Mark , Sosinsky Gina 
Published: July 2020

Abstract
Understanding the light-harvesting properties of algae and higher plants are a fundamental topic in photosynthesis research. Much oceanographic research has focused on characterizing the in vivo chlorophyll-specific absorption coefficient, a*ph (λ) in phytoplankton because it serves as an input variable for bio-optical modeling of photosynthesis using remote sensing instrumentation such as moorings, drifters, and satellites. Values of a*ph (λ) vary spectrally and the magnitude depends on accessory pigments, photo-protective pigments, and pigment packaging effects. Several studies have shown that the contribution of cellular characteristics to a*ph(λ) varies with growth conditions including temperature, light, and nutrients. It has been shown that a*ph (λ) values in Phaeocystis vary predictably at 4°C over light intensities under light limitation. Phaeocystis demonstrated significant pigment package effects that depended on single cell diameter and thylakoid membrane stacking. Using thick sections obtained from fixed and embedded cultures of colonial P. antarctica, we calculated tomographic reconstructions of individual chloroplasts under light-limiting conditions for net photosynthesis in order to gain an understanding of the continuity of thylakoid membranes and understand the spatial relationship between the pyrenoid, the starch containing organelle, and thylakoid membranes.
Colocalization Of Markers Of The Endocytic And Biosynthetic Pathways In Multivesicular Bodies Of Murine Alveolar Type Ii Epithelial Cells
Authors: Na Cheng-Lun , Weaver Timothy E 
Published: July 2020

Abstract
Immunocytochemistry studies have established that multivesicular bodies (MVBs) in alveolar type II epithelial cells are important for processing pulmonary surfactant protein precursors (proSP; Voorhout et al., 1992 and 1993). Localization of pulmonary surfactant protein A (SP-A) gold and cationic ferritin to the MVBs demonstrated that MVBs also serve as endosomal/lysosomal compartments for recycling SPs (Williams et al., 1984, Ryan et al., 1989). However, these studies did not elucidate whether the biosynthesis of pulmonary SPs and endocytosis occur in the same MVBs. In this study, we used primary murine alveolar type II epithelial cell cultures as a model to determine if the biosynthetic and endocytic compartments colocalized in MVBs. The endocytic compartments of MVBs were identified using BSA gold conjugates, while the biosynthetic pathway was detected with antibodies directed against proSPs.
Alveolar type II epithelial cells isolated from 6 weeks old C57B/6 mice were grown on Transwell cell inserts in the presence of 6 nm BSA gold conjugates (BSAG6) adjusted to final concentration of OD520 5.0 in DMEM, 25 mM HEPES, and 10% fetal bovine serum, pH 7.3, at 37 °C for 20 hours.
Ultrastructure of Candida Albicans And Saccharomyces Cerevisiae After Treatment With Sch 56301 (An Aureobasidin)
Authors: Dovey-Hartman BJ , Cramer C , Greene J , Shaw KJ , Hare RS , DiDomenico B 
Published: July 2020

Abstract
Aureobasidins are cyclic depsipeptide natural products that have been shown to be fungicidal against a wide variety of fungi. We have studied the effect of an aureobasidin-like compound, SCH 56301 on the morphology and cytology of yeast cells. For both, Candida albicans and Saccharomyces cerevisiae, the normal cell cycle is disrupted by sub-lethal concentrations of the compound. In Saccharomyces, cells accumulate at the G2/M border of the cell cycle, DNA replication is essentially complete and a short nuclear spindle is visible; however, nuclear migration and spindle elongation do not occur and consequently a small round daughter cell remains attached to the mother cell. Changes in cell wall morphology are visible at old bud scars remaining on mother cells. Under the conditions of preparation of the specimens, there may have been insufficient cross-linking during treatment with SCH 56301 so that intracellular pressure appears to be pushing on a weakened cell wall at these points.
Centrosome Structure And Function Is Altered By Experimental Manipulations With Formamide: Implications For Abnormal Cell Divisions During Cancer
Authors: Schatten Heide , Hueser Christopher N , Chakrabarti Amitabha 
Published: July 2020

Abstract
The formation of abnormal mitosis associated with cancer has been intriguing for many decades. While microtubules had been the focus of previous studies, recent research has focused on centrosomes, microtubule organizing centers which organize the mitotic apparatus during cell division. During normal mitosis centrosomes form two poles but in cancer, centrosomes can form three, four, or more poles, and organize tripolar, quadripolar, and multipolar mitoses, respectively. This has severe consequences for genomic stability because chromosomes are separated unequally to three, four, or more poles. This can result in aneuploidy and gene amplifications with multiple defects in cellular regulation. It can result in malignancy that is accompanied by cell cycle imbalances and abnormal cell proliferation. While radiation and chemical agents are known to damage DNA and can lead to cell cycle abnormalities, the damage of centrosome structure leading to abnormal mitosis deserves also consideration.
Mapping Phosphorus In Macromolecular Assemblies At Near Single Atom Sensitivity By Stem-Eels
Authors: Leapman RD , Rizzo NW 
Published: July 2020

Abstract
In principle, electron energy loss spectroscopy (EELS) in the scanning transmission electron microscope (STEM) should be able to detect single atoms of phosphorus in biological macromolecules. Such a capability would provide a direct method for measuring the degree of phosphorylation or nucleotide binding which are important in determining the functional states of protein assemblies. Although it has already been possible to map heavy elements, e.g., uranium, at near single atom sensitivity, this has not yet been achievable for lighter atoms like phosphorus. One difficulty in imaging light atoms in a biological specimen is that there is insufficient contrast to visualize the atoms directly so, in a stationary probe analysis, it is not known where to place the probe. Identifying single phosphorus atoms therefore necessarily involves compositional mapping in which EELS information is collected pixel by pixel, a technique known as spectrum-imaging. Recently, improvements have been made in the acquisition of such images, especially the ability to correct for specimen drift in a robust fashion.