scholarly journals Canine bocavirus-2 infection and its possible association with encephalopathy in domestic dogs

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0255425
Author(s):  
Chutchai Piewbang ◽  
Sabrina Wahyu Wardhani ◽  
Wichan Dankaona ◽  
Sitthichok Lacharoje ◽  
Poowadon Chai-in ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Control Group ◽  
Normal Brain ◽  
Evolutionary Analysis ◽  
Histological Changes ◽  
Brain Infection ◽  
Transmission Electron ◽  
Viral Particles ◽  
Cellular Tropism

Canine bocaviruses (CBoVs) have been recognized as pathogens associated with intestinal diseases. Hematogenous spreading caused by CBoV has been documented and may potentiate the virus entry across the blood-brain barrier to initiate a brain infection. This study focused attention on CBoV detection in cases of encepahlopathy and attempted to determine its viral localization. A total of 107 dog brains that histologically exhibited encephalopathy (ED) were investigated for the presence of CBoVs using polymerase chain reaction (PCR). Thirty-three histologically normal brain samples from dogs were used as a control group (CD). CBoV-2 was detected in 15 ED dogs (14.02%) but not in CD dogs (p = 0.02), while no CBoV-1 and -3 were detected. Among the CBoV-2 positive dogs, brain histological changes were characterized by nonsuppurative encephalitis, with inclusion body-like materials in some brains. In situ hybridization (ISH) and transmission electron microscopy (TEM) confirmed the presence of CBoV-2 viral particles in glial cells, supporting neurotropism of this virus. ISH signals were also detected in the intestines, lymphoid organs, and the heart, suggesting both enteral and parenteral infections of this virus. Whole genome characterization and evolutionary analysis revealed genetic diversity of CBoV-2 sequences and it was varying among the different countries where the virus was detected. This study points to a possible association of CBoV-2 with encephalopathy in dogs. It also highlights the genetic diversity and cellular tropism of this virus.

scholarly journals Cellular tropism of SARS-CoV-2 in the respiratory tract of Syrian hamsters and B6.Cg-Tg(K18-ACE2)2Prlmn/J transgenic mice

2021 ◽  
pp. 030098582110430
Author(s):  
Hui-Ling Yen ◽  
Sophie Valkenburg ◽  
Sin Fun Sia ◽  
Ka Tim Choy ◽  
J. S. Malik Peiris ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Lung Parenchyma ◽  
Productive Infection ◽  
Type I ◽  
Syrian Hamsters ◽  
Transmission Electron ◽  
Type Ii Pneumocytes ◽  
Viral Particles ◽  
Cellular Tropism ◽  
Conducting Airways

Several animal models have been developed to study the pathophysiology of SARS-CoV-2 infection and to evaluate vaccines and therapeutic agents for this emerging disease. Similar to infection with SARS-CoV-1, infection of Syrian hamsters with SARS-CoV-2 results in moderate respiratory disease involving the airways and lung parenchyma but does not lead to increased mortality. Using a combination of immunohistochemistry and transmission electron microscopy, we showed that the epithelium of the conducting airways of hamsters was the primary target for viral infection within the first 5 days of infection, with little evidence of productive infection of pneumocytes. At 6 days postinfection, antigen was cleared but parenchymal damage persisted, and the major pathological changes resolved by day 14. These findings are similar to those previously reported for hamsters with SARS-CoV-1 infection. In contrast, infection of K18-hACE2 transgenic mice resulted in pneumocyte damage, with viral particles and replication complexes in both type I and type II pneumocytes together with the presence of convoluted or cubic membranes; however, there was no evidence of virus replication in the conducting airways. The Syrian hamster is a useful model for the study of SARS-CoV-2 transmission and vaccination strategies, whereas infection of the K18-hCE2 transgenic mouse results in lethal disease with fatal neuroinvasion but with sparing of conducting airways.

EXPLORING THE CHRONIC MORTALITY AFFECTING ABALONES IN TAIWAN: DIFFERENTIATION OF ABALONE HERPESVIRUS-ASSOCIATED ACUTE INFECTION FROM CHRONIC MORTALITY BY PCR AND IN SITU HYBRIDIZATION AND HISTOPATHOLOGY

2016 ◽  
Vol 42 (01) ◽  
pp. 1-9 ◽  
Author(s):  
I-Wen Chen ◽  
Pen-Heng Chang ◽  
Min-Shou Chen ◽  
Tristan Renault ◽  
Meei-Mei Chen ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Acute Infection ◽  
Extended Period ◽  
Haliotis Diversicolor Supertexta ◽  
Transmission Electron ◽  
Viral Particles ◽  
Primer Sets ◽  
Diversicolor Supertexta ◽  
Pcr In Situ

Abalone herpesvirus (AbHV) infection of cultured abalones Haliotis diversicolor supertexta induced acute high mortality in 2003. Years later, sporadic mortality was noted for an extended period of months, resulting in high cumulative mortality. Moribund abalones were analyzed using PCR, in situ hybridization, and histopathology, because thus far no viral particles have been observed by transmission electron microscopy. PCR using 20 primer sets, specifically designed from sequences of acute AbHV infection, failed to amplify any products from abalones suffering from chronic mortality. Subsequently, a 1406-bp sequence was amplified from chronic moribund abalones, and this sequence showed a 92% (553 bp/602 bp) homology with the gene of an AbHV Taiwan isolate (NCBI serial no. KF537536.1), suggestive of an AbHV pathotype. Histopathology of AbHV pathotype infection showed hemocyte infiltration in the lamina propia of the digestive tract, and hemocytes of various stages were evident, as well as the loss of seminal tubules in the gonad. In situ hybridization revealed that in AbHV infection, positive signals were restricted to the neural ganglia, while in AbHV pathotype infection, positive signals were observed only in the hemocytes. It appeared that the tropism of AbHV shifted from mainly neurotropic in AbHV infection to mainly hemocytotropic in abalone suffering from chronic mortality. Abalone shriveling syndrome-associated virus co-infection was detected in some of AbHV pathotype infection events. Further studies are needed to better understand the pathogenesis of AbHV pathotype affecting H. diversicolor in Taiwan.

scholarly journals Characterization of a novel alloherpesvirus from Atlantic cod (Gadus morhua)

2011 ◽  
Vol 24 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Mar Marcos-Lopez ◽  
Thomas B. Waltzek ◽  
Ronald P. Hedrick ◽  
Dolores V. Baxa ◽  
Amber F. Garber ◽  
...  
Keyword(s):  
Gadus Morhua ◽  
Virus Isolation ◽  
Atlantic Cod ◽  
International Committee ◽  
Atpase Subunit ◽  
Transmission Electron ◽  
Viral Particles ◽  
Infected Cells

Alloherpesviruses affect freshwater and marine fish species. The aim of the current study was to characterize a novel alloherpesvirus in Atlantic cod ( Gadus morhua). Samples were processed for histopathology, transmission electron microscopy (TEM), virus isolation, molecular characterization, and in situ hybridization (ISH). Histopathology revealed that the infection was restricted to the gills and that it induced cytomegaly in infected cells. By TEM, numerous viral particles with morphology compatible with a herpesvirus were observed inside the cytomegalic cells. To characterize this new agent, polymerase chain reaction amplified regions of the ATPase subunit of the terminase, and DNA polymerase genes were sequenced. Phylogenetic analysis revealed strongest similarity with alloherpesviruses belonging to the genus Ictalurivirus and Salmonivirus. The ISH showed specific labeling of nuclear inclusions in the cytomegalic cells. While virus isolation was unsuccessful, the results obtained through different diagnostic tests in the present study confirm the discovery of a new alloherpesvirus affecting Atlantic cod. The authors propose the formal species designation Gadid herpesvirus 1 (GaHV-1) to be considered for approval by the International Committee on the Taxonomy of Viruses.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

In situ REM imaging of surface processes on ceramic bulk crystals from 300 to 1670 K in a conventional TEM

1991 ◽  
Vol 49 ◽  
pp. 660-661
Author(s):  
Z. L. Wang ◽  
J. Bentley
Keyword(s):  
High Temperatures ◽  
Image Resolution ◽  
Atomic Processes ◽  
Crystal Surfaces ◽  
Beam Radiation ◽  
Surface Areas ◽  
Transmission Electron ◽  
Reflection Electron Microscopy ◽  
Gas Reactions

Studying the behavior of surfaces at high temperatures is of great importance for understanding the properties of ceramics and associated surface-gas reactions. Atomic processes occurring on bulk crystal surfaces at high temperatures can be recorded by reflection electron microscopy (REM) in a conventional transmission electron microscope (TEM) with relatively high resolution, because REM is especially sensitive to atomic-height steps.Improved REM image resolution with a FEG: Cleaved surfaces of a-alumina (012) exhibit atomic flatness with steps of height about 5 Å, determined by reference to a screw (or near screw) dislocation with a presumed Burgers vector of b = (1/3)<012> (see Fig. 1). Steps of heights less than about 0.8 Å can be clearly resolved only with a field emission gun (FEG) (Fig. 2). The small steps are formed by the surface oscillating between the closely packed O and Al stacking layers. The bands of dark contrast (Fig. 2b) are the result of beam radiation damage to surface areas initially terminated with O ions.

Role of boundaries in the crystallization of amorphous films

1988 ◽  
Vol 46 ◽  
pp. 626-627
Author(s):  
D. A. Smith
Keyword(s):  
Low Temperature ◽  
Amorphous State ◽  
Nucleation And Growth ◽  
Amorphous Films ◽  
Island Nucleation ◽  
Surface Steps ◽  
Transmission Electron ◽  
Component Systems ◽  
Temperature Deposition

The nucleation and growth processes which lead to the formation of a thin film are particularly amenable to investigation by transmission electron microscopy either in situ or subsequent to deposition. In situ studies have enabled the observation of island nucleation and growth, together with addition of atoms to surface steps. This paper is concerned with post-deposition crystallization of amorphous alloys. It will be argued that the processes occurring during low temperature deposition of one component systems are related but the evidence is mainly indirect. Amorphous films result when the deposition conditions such as low temperature or the presence of impurities (intentional or unintentional) preclude the atomic mobility necessary for crystallization. Representative examples of this behavior are CVD silicon grown below about 670°C, metalloids, such as antimony deposited at room temperature, binary alloys or compounds such as Cu-Ag or Cr O2, respectively. Elemental metals are not stable in the amorphous state.

In situ observations of electromigration induced void behavior

1995 ◽  
Vol 53 ◽  
pp. 244-245
Author(s):  
T. Marieb ◽  
J. C. Bravman ◽  
P. Flinn ◽  
D. Gardner ◽  
M. Madden
Keyword(s):  
Electron Microscopy ◽  
Void Nucleation ◽  
Plan View ◽  
Transmission Electron ◽  
Nucleation Sites ◽  
Microelectronics Industry ◽  
In Situ Observations ◽  
Backscatter Electron Detector ◽  
Voltage Scanning

Electromigration and stress voiding have been active areas of research in the microelectronics industry for many years. While accelerated testing of these phenomena has been performed for the last 25 years[1-2], only recently has the introduction of high voltage scanning electron microscopy (HVSEM) made possible in situ testing of realistic, passivated, full thickness samples at high resolution.With a combination of in situ HVSEM and post-testing transmission electron microscopy (TEM) , electromigration void nucleation sites in both normal polycrystalline and near-bamboo pure Al were investigated. The effect of the microstructure of the lines on the void motion was also studied.The HVSEM used was a slightly modified JEOL 1200 EX II scanning TEM with a backscatter electron detector placed above the sample[3]. To observe electromigration in situ the sample was heated and the line had current supplied to it to accelerate the voiding process. After testing lines were prepared for TEM by employing the plan-view wedge technique [6].

A TEM study of the microstructure of avian eggshells

1992 ◽  
Vol 50 (2) ◽  
pp. 1102-1103
Author(s):  
S. Q. Xiao ◽  
S. Baden ◽  
A. H. Heuer
Keyword(s):  
Electron Microscope ◽  
Calcium Carbonate ◽  
Nucleation And Growth ◽  
Growth Mechanisms ◽  
Shell Surface ◽  
Thin Sections ◽  
Polycrystalline Metals ◽  
Transmission Electron ◽  
Nucleation And Growth Mechanisms

The avian eggshell is one of the most rapidly mineralizing biological systems known. In situ, 5g of calcium carbonate are crystallized in less than 20 hrs to fabricate the shell. Although there have been much work about the formation of eggshells, controversy about the nucleation and growth mechanisms of the calcite crystals, and their texture in the eggshell, still remain unclear. In this report the microstructure and microchemistry of avian eggshells have been analyzed using transmission electron microscope (TEM) and energy dispersive spectroscopy (EDS).Fresh white and dry brown eggshells were broken and fixed in Karnosky's fixative (kaltitanden) for 2 hrs, then rinsed in distilled H2O. Small speckles of the eggshells were embedded in Spurr medium and thin sections were made ultramicrotome.The crystalline part of eggshells are composed of many small plate-like calcite grains, whose plate normals are approximately parallel to the shell surface. The sizes of the grains are about 0.3×0.3×1 μm3 (Fig.l). These grains are not as closely packed as man-made polycrystalline metals and ceramics, and small gaps between adjacent grains are visible indicating the absence of conventional grain boundaries.

Dynamic studies of silicide-mediated crystallization of amorphous silicon

1992 ◽  
Vol 50 (2) ◽  
pp. 1352-1353
Author(s):  
C. Hayzelden ◽  
J. L. Batstone
Keyword(s):  
Ion Implantation ◽  
Solid Phase ◽  
Metallic Phase ◽  
Single Crystal Substrate ◽  
Free Electrons ◽  
Melt Temperature ◽  
Transmission Electron ◽  
Crystal Substrate ◽  
High Resolution Tem

Epitaxial reordering of amorphous Si(a-Si) on an underlying single-crystal substrate occurs well below the melt temperature by the process of solid phase epitaxial growth (SPEG). Growth of crystalline Si(c-Si) is known to be enhanced by the presence of small amounts of a metallic phase, presumably due to an interaction of the free electrons of the metal with the covalent Si bonds near the growing interface. Ion implantation of Ni was shown to lower the crystallization temperature of an a-Si thin film by approximately 200°C. Using in situ transmission electron microscopy (TEM), precipitates of NiSi2 formed within the a-Si film during annealing, were observed to migrate, leaving a trail of epitaxial c-Si. High resolution TEM revealed an epitaxial NiSi2/Si(l11) interface which was Type A. We discuss here the enhanced nucleation of c-Si and subsequent silicide-mediated SPEG of Ni-implanted a-Si.Thin films of a-Si, 950 Å thick, were deposited onto Si(100) wafers capped with 1000Å of a-SiO2. Ion implantation produced sharply peaked Ni concentrations of 4×l020 and 2×l021 ions cm−3, in the center of the films.

In situ TEM measurements of the electrical properties of interface dislocations

1992 ◽  
Vol 50 (2) ◽  
pp. 1338-1339
Author(s):  
F. M. Ross ◽  
R. Hull ◽  
D. Bahnck ◽  
J. C. Bean ◽  
L. J. Peticolas ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Electronic Device ◽  
In Situ Tem ◽  
Device Performance ◽  
Misfit Dislocations ◽  
Electrical Characteristics ◽  
Strained Layer ◽  
Transmission Electron ◽  
Interfacial Dislocations

We describe an investigation of the electrical properties of interfacial dislocations in strained layer heterostructures. We have been measuring both the structural and electrical characteristics of strained layer p-n junction diodes simultaneously in a transmission electron microscope, enabling us to correlate changes in the electrical characteristics of a device with the formation of dislocations.The presence of dislocations within an electronic device is known to degrade the device performance. This degradation is of increasing significance in the design and processing of novel strained layer devices which may require layer thicknesses above the critical thickness (hc), where it is energetically favourable for the layers to relax by the formation of misfit dislocations at the strained interfaces. In order to quantify how device performance is affected when relaxation occurs we have therefore been investigating the electrical properties of dislocations at the p-n junction in Si/GeSi diodes.

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