scholarly journals Ultra- and micro-structural changes of respiratory tracts in SARS-CoV-2 infected Syrian hamsters

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Myeon-Sik Yang ◽  
Byung Kwan Oh ◽  
Daram Yang ◽  
Eun Young Oh ◽  
Yeonhwa Kim ◽  
...  
Keyword(s):  
Structural Changes ◽  
Alveolar Epithelium ◽  
Inflammatory Cells ◽  
Alveolar Wall ◽  
Lamellar Bodies ◽  
Electron Microscopic ◽  
Syrian Hamsters ◽  
Electron Lucent

AbstractThe severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) pandemic is causing a global crisis. It is still unresolved. Although many therapies and vaccines are being studied, they are still in their infancy. As this pandemic continues, rapid and accurate research for the development of therapies and vaccines is needed. Therefore, it is necessary to understand characteristics of diseases caused by SARS-CoV-2 through animal models. Syrian hamsters are known to be susceptible to SARS-CoV-2. They were intranasally inoculated with SARS-CoV-2. At 2, 4, 8, 12, and 16 days post-infection (dpi), these hamsters were euthanized, and tissues were collected for ultrastructural and microstructural examinations. Microscopic lesions were prominent in the upper and lower respiratory tracts from 2 and 4 dpi groups, respectively. The respiratory epithelium in the trachea, bronchiole, and alveolar showed pathological changes. Inflammatory cells including neutrophils, lymphocytes, macrophages, and eosinophils were infiltrated in/around tracheal lamina propria, pulmonary vessels, alveoli, and bronchiole. In pulmonary lesions, alveolar wall was thickened with infiltrated inflammatory cells, mainly neutrophils and macrophages. In the trachea, epithelial damages started from 2 dpi and recovered from 8 dpi, consistent with microscopic results, High levels of SARS-CoV-2 nucleoprotein were detected at 2 dpi and 4 dpi. In the lung, lesions were most severe at 8 dpi. Meanwhile, high levels of SARS-CoV-2 were detected at 4 dpi. Electron microscopic examinations revealed cellular changes in the trachea epithelium and alveolar epithelium such as vacuolation, sparse micro-organelle, and poor cellular margin. In the trachea epithelium, the number of cytoplasmic organelles was diminished, and small vesicles were prominent from 2 dpi. Some of these electron-lucent vesicles were filled with virion particles. From 8 dpi, the trachea epithelium started to recover. Because of shrunken nucleus and swollen cytoplasm, the N/C ratio of type 2 pneumocyte decreased at 8 and 12 dpi. From 8 dpi, lamellar bodies on type 2 pneumocyte cytoplasm were increasingly observed. Their number then decreased from 16 dpi. However, there was no significant change in type 1 pneumocyte. Viral vesicles were only observed in the cytoplasm of type 2 pneumocyte. In conclusion, ultra- and micro-structural changes presented in this study may provide useful information for SARS-CoV-2 studies in various fields.

Watermelon mosaic virus 1 and 2 in Queensland cucurbit crops

1978 ◽  
Vol 29 (6) ◽  
pp. 1235 ◽  
Author(s):  
RS Greber
Keyword(s):  
Mosaic Virus ◽  
Virus Type ◽  
Electron Microscopic Examination ◽  
Watermelon Mosaic Virus ◽  
Electron Microscopic ◽  
Virus Particles ◽  
Cellular Inclusions ◽  
Differential Hosts

Watermelon mosaic virus type 1 (WMV-1) has not previously been reported from Australia and has become prevalent in Queensland only since 1970. Watermelon mosaic virus type 2 (WMV-2) continues to reach a high incidence in marrow (Cucurbita pepo) and pumpkin (Cucurbita maxima and Cucurbita moschata) crops, WMV-2 is rarely isolated from watermelons (Citrullus vulgaris) in which epidemics of WMV-1 now cause serious reductions in yield. The Queensland Blue cultivar of C. maxima, the most important cucurbit crop, produces severely distorted fruit following infection by WMV-1, although it is little affected by WMV-2. Physical properties of these WMV isolates and electron microscopic examination of the virus particles and associated cellular inclusions showed them to be similar to those reported elsewhere, but there were some distinctive host reactions for the WMV-2 isolates. No resistance to either WMV-1 or WMV-2 was found in commercially available C. pepo, C. maxima or C. vulgaris. The resistance of Cucumis metuliferus to Australian WMV-1 isolates was confirmed, and a source of resistance to both WMV-1 and WMV-2 was found in Lagenaria siceravia. Methods of separation of WMV-1 and WMV-2 from mixed isolates and methods for the identification of each on differential hosts and by serology were shown to be effective.

Structural changes associated with solid-state reactions in Al–Ag–Mg alloys

1986 ◽  
Vol 19 (3) ◽  
pp. 174-180 ◽  
Author(s):  
S. M. Cousland ◽  
G. R. Tate
Keyword(s):  
Structural Changes ◽  
Mg Alloys ◽  
Mg Alloy ◽  
Solid State Reactions ◽  
Phase Volume ◽  
Alloy Type ◽  
Equilibrium Phases ◽  
Precipitated Phases

The structural changes associated with the precipitation of metastable and equilibrium phases during decomposition of three supersaturated Al-rich Al–Ag–Mg alloys at 393, 456 and 508 K have been established by analysing the diffraction of monochromatic X-radiation by single-crystal alloy plates. Precipitated phases observed were: (a) in the Al–0.54 at.% Ag–4.49 at.% Mg alloy, type 1 Guinier–Preston zones, T′ phase, T phase; (b) in the Al–0.87 at.% Ag–1.80 at.% Mg alloy, type 1 Guinier–Preston zones, type 2 Guinier–Preston zones (a newly observed body-centred tetragonal compound, a = 4.13, c = 8.60 Å, space group I 41/amd), T′ phase, η phase; (c) in the Al–1.30 at.% Ag–1.05 at.% Mg alloy, type 1 Guinier–Preston zones, type 2 Guinier–Preston zones, γ phase. Volume fractions of the precipitated phases, sizes of the precipitates and orientations of cell axes relative to the axes of the Al lattice are given for various stages of each decomposition sequence.

scholarly journals STUDIES ON GONOCOCCUS INFECTION

1971 ◽  
Vol 134 (4) ◽  
pp. 886-906 ◽  
Author(s):  
John Swanson ◽  
Stephen J. Kraus ◽  
Emil C. Gotschlich
Keyword(s):  
Animal Cell ◽  
Electron Microscopic Examination ◽  
Electron Microscopic ◽  
Fluid Medium ◽  
Thin Sections ◽  
Outer Membranes ◽  
Different Strains ◽  
Type 3

The four colony types of several different strains of gonococci were isolated by selective transfers on agar. These colony variants differed in the degree of autoagglutination which occurred when they were grown in fluid medium. It was found that this clumping behavior was related to the colonial type, with type 2 isolates exhibiting the greatest autoagglutination followed by types 3, 1, and 4. Electron microscopic examination of thin sections indicated that the clumping in fluid medium was mediated by peculiar zones of adherence of the outer membranes of gonococci. These resembled the gap junctions seen in animal cell systems but differed in that the gonococcal membranes involved in the zone of adherence did not bear typical surface modifications. Electron microscopic study of negatively stained specimens of gonococci revealed that pili with a diameter of approximately 85 A and a length up to 4 µ were present on the surfaces of all type 1 and type 2 gonococci examined, and were not seen on any type 3 or 4 gonococci. The consistent presence of pili on type 1 and type 2 gonococci which are virulent colony forms and the lack of pili on avirulent colony types 3 and 4 suggests a relationship between the gonococcal pili and pathogenetic potential of the organisms.

scholarly journals Renal structure in type 2 diabetes: facts and misconceptions

2020 ◽  
Vol 33 (5) ◽  
pp. 901-907 ◽  
Author(s):  
Angelo Di Vincenzo ◽  
Silvia Bettini ◽  
Lucia Russo ◽  
Sara Mazzocut ◽  
Michael Mauer ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Diabetic Nephropathy ◽  
Structural Changes ◽  
Clinical Manifestations ◽  
Renal Diseases ◽  
Diabetic Patients ◽  
Renal Lesion ◽  
Renal Lesions

Abstract The clinical manifestations of diabetic nephropathy are similar in type 1 and type 2 diabetes, while the renal lesions may differ. Indeed, diabetic glomerulopathy is the predominant renal lesion in type 1 diabetes, although also tubular, interstitial and arteriolar lesions are present in the advanced stages of renal disease. In contrast, in type 2 diabetes renal lesions are heterogeneous, and a substantial number of type 2 diabetic patients with diabetic kidney disease have mild or absent glomerulopathy with tubulointerstitial and/or arteriolar abnormalities. In addition, a high prevalence of non-diabetic renal diseases, isolated or superimposed on classic diabetic nephropathy lesions have been reported in patients with type 2 diabetes, often reflecting the bias of selecting patients for unusual clinical presentations for renal biopsy. This review focuses on renal structural changes in type 2 diabetes, emphasizing the contribution of research kidney biopsy studies to the understanding of the pathogenesis of DKD and of the structural lesions responsible for the different clinical phenotypes. Also, kidney biopsies could provide relevant information in terms of renal prognosis, and help to understand the different responses to different therapies, especially SGLT2 inhibitors, thus allowing personalized medicine.

scholarly journals Analysis of opacification patterns in intraocular lenses (IOL)

2021 ◽  
Vol 6 (1) ◽  
pp. e000589
Author(s):  
Marc Mackert ◽  
Daniel Rudolf Muth ◽  
Efstathios Vounotrypidis ◽  
Constanze Deger ◽  
David Goldblum ◽  
...  
Keyword(s):  
Microscopic Analysis ◽  
Intraocular Lenses ◽  
University Hospital ◽  
Electron Microscopic ◽  
Pathological Conditions ◽  
Single Piece ◽  
Processing Properties ◽  
Combination Of Material

ObjectiveIntraocular lens (IOL) opacification may cause severe visual impairment. The pathogenesis remains unclear. The aim of this study was to analyse opacification patterns in different IOLs. Therefore, this multicentre, retrospective, observational study was conducted at Ludwig-Maximilians-University, Munich, Germany and University-Hospital Basel, Switzerland.Methods and analysisIn this study, 75 opacified IOLs were identified and classified after extraction. Macroscopical photo documentation, light and electron microscopic analysis were done.Results68 acrylic-hydrophilic single-piece-IOLs, 1 acrylic-hydrophilic 3-piece-IOL, 6 acrylic-hydrophobic 3-piece-IOLs were extracted. The dataset comprised IOLs known for opacification and IOLs not having been reported yet. 67 IOLs showed a fine-granular and 8 IOLs a crust-like opacification pattern. According to literature, 62 of the fine-granular opacified IOLs were graded into type 1 (processing/packaging-induced primary opacification) and 13 into type 2 (secondary opacification of unknown aetiology). The anterior surface of the IOLs was affected in all 75 IOLs, the posterior surface only in 23 cases. Of all 67 fine-granular IOLs, 43 had a central defect and 21 had a zone without opacification (clear islet).ConclusionIn our series, the morphology of IOL opacification did not follow the existing pathogenetic classification that strictly discriminates between primary and secondary causes. Fine-granular IOL opacification occurs with similar patterns in both type 1 and type 2 IOL opacification, while a crust-like pattern was only detected in type 2 IOL opacifications. Consequently, susceptibility of an IOL to opacification is caused by a multifactorial combination of material and processing properties as well as individual (pathological) conditions of the patient.

scholarly journals Resetting proteostasis with ISRIB promotes epithelial differentiation to attenuate pulmonary fibrosis

2021 ◽  
Vol 118 (20) ◽  
pp. e2101100118
Author(s):  
Satoshi Watanabe ◽  
Nikolay S. Markov ◽  
Ziyan Lu ◽  
Raul Piseaux Aillon ◽  
Saul Soberanes ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Lung Fibrosis ◽  
Alveolar Epithelium ◽  
Protein Translation ◽  
Alveolar Type ◽  
Fatal Disease ◽  
Epithelial Repair ◽  
Old Mice

Pulmonary fibrosis is a relentlessly progressive and often fatal disease with a paucity of available therapies. Genetic evidence implicates disordered epithelial repair, which is normally achieved by the differentiation of small cuboidal alveolar type 2 (AT2) cells into large, flattened alveolar type 1 (AT1) cells as an initiating event in pulmonary fibrosis pathogenesis. Using models of pulmonary fibrosis in young adult and old mice and a model of adult alveologenesis after pneumonectomy, we show that administration of ISRIB, a small molecule that restores protein translation by EIF2B during activation of the integrated stress response (ISR), accelerated the differentiation of AT2 into AT1 cells. Accelerated epithelial repair reduced the recruitment of profibrotic monocyte-derived alveolar macrophages and ameliorated lung fibrosis. These findings suggest a dysfunctional role for the ISR in regeneration of the alveolar epithelium after injury with implications for therapy.

scholarly journals An assessment of morphological and pathological changes in paravertebral muscle degeneration using imaging and histological analysis: a cross-sectional study

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Ding-Chao Zhu ◽  
Jia-Hao Lin ◽  
Jia-Jing Xu ◽  
Qiang Guo ◽  
Yi-Han Wang ◽  
...  
Keyword(s):  
Histological Analysis ◽  
Inflammatory Cells ◽  
Fatty Degeneration ◽  
High Signal ◽  
Pathological Changes ◽  
Paravertebral Muscle ◽  
Inflammatory Edema ◽  
Type 3

Abstract Background The high signal of paravertebral muscle (PVM) on T2-weighted image (T2WI) is usually considered to be fatty degeneration. However, it is difficult to distinguish inflammatory edema from fatty degeneration on T2WI. The purpose of this study was to identify different types of PVM high signal in patients with low back pain (LBP) through magnetic resonance imaging (MRI) and histology. Methods Seventy patients with LBP underwent MRI. The signal change of multifidus both on T2WI and fat suppression image (FSI) was quantified by Image J. Furthermore, 25 of the 70 patients underwent surgery for degenerative lumbar disease and their multifidus were obtained during the operation. Histological analysis of the samples was performed by HE staining. Result Three types of PVM signal changes were identified from the MRI. Type 1 (n = 36) indicated fatty degeneration characterized by a high signal on T2WI and low signal on FSI. High signal on both T2WI and FSI, signifying type 2 meant inflammatory edema (n = 9). Type 3 (n = 25) showed high signal on T2WI and partial signal suppression on FSI, which meant a combination of fatty degeneration and inflammatory edema. Histological results were consistent with MRI. Among the 25 patients who underwent surgery, type 1 (n = 14) showed adipocytes infiltration, type 2 (n = 3) showed inflammatory cells infiltration and type 3 (n = 8) showed adipocytes and inflammatory cells infiltration. Conclusion From our results, there are three types of pathological changes in patients with PVM degeneration, which may help to decide on targeted treatments for LBP.

Pathogenesis: Structural Changes in the Kidneys in Type 1 and Type 2 Diabetes

2022 ◽  
pp. 105-154
Author(s):  
Guillermo A. Herrera ◽  
Luis del Pozo-Yauner ◽  
Jeffrey J. Aufman ◽  
Elba A. Turbat-Herrera
Keyword(s):  
Type 2 Diabetes ◽  
Structural Changes

Crystallographic and transport studies on AsF5 intercalated graphite from 4.2 to 295 K. II. Effects of structural transformations and demixing on basal plane and c-axis electrical resistivity

1988 ◽  
Vol 3 (1) ◽  
pp. 97-104 ◽  
Author(s):  
E. McRae ◽  
M. Lelaurain ◽  
J. F. Marêché ◽  
G. Furdin ◽  
A. Hérold ◽  
...  
Keyword(s):  
Basal Plane ◽  
Structural Changes ◽  
Structural Data ◽  
Structural Transformations ◽  
Structural Modifications ◽  
Intercalated Graphite ◽  
Transport Studies ◽  
Conductivity Models

Part I of this study has shown that first stage AsF5 intercalated graphite samples can be classified into two types of compounds, depending upon the nature of the structural modifications they undergo upon lowering the temperature from 295 to 4.2 K. These structural changes are related to demixing of the species contained within the intercalate resulting in the formation of phases rich in AsF5, AsF−6 − AsF5, or AsF3 depending on the degree to which the AsF5 has been converted into AsF−6 and AsF3. Resistivity studies have been carried out in the basal plane [ρa (T)] and along the c axis [ρc (T)]. The type 1 compounds, in which the AsF5 has undergone little conversion, manifest a ρa (T) transition related to the incommensurate-to-commensurate (I⇉C) transformation of the AsF5 in-plane unit cell and a rapid, structureless 300 to 200 K decrease in ρc (T). The type 2 compounds involving a greater degree of conversion of AsF5 into AsF3 and AsF6 yield more complex ρc (T) behavior from 300 to 200 K attributed to the more involved ordering phenomena; no anomalies are seen in ρa (T). In the case of the stage 2 compounds, changes in ρc (T) are seen down to lower temperatures in accord with structural data indicating a downshift of the I⇉C transformation by ∼ 70 K. The transport results are discussed in the light of the crystallographic data and the low-temperature results are analyzed within the framework of proposed conductivity models.

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