scholarly journals Noise-induced gastric lesions: a light and electron microscopy study of the rat gastric wall exposed to low frequency noise

2012 ◽  
Vol 49 (1) ◽  
pp. 82-88 ◽  
Author(s):  
Jorge Fonseca ◽  
José Martins-dos-Santos ◽  
Pedro Oliveira ◽  
Nuno Laranjeira ◽  
Artur Aguas ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gastric Wall ◽  
Low Frequency ◽  
Collagen Iv ◽  
Control Group ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Transmission Electron ◽  
Significant Difference

CONTEXT: Only a few studies evaluated the digestive alterations caused by low frequency noise (LFN) and most focused only on mucosal alterations. OBJECTIVES: To investigate the morphological injury of LFN-exposed gastric wall, beyond the epithelial layer. METHODS: Wistar rats were exposed to low frequency noise (LFN), during increasing periods, 1 to 13 weeks. A control group was kept in silence. Gastric specimens were studied using: (i) light microscopy with hematoxylin-eosin and immunostaining for collagens; (ii) transmission electron microscopy; (iii) morphometry allowing statistical analysis. RESULTS: Submucosa of all LFN-exposed animals exhibit increased thickness with fibrous proliferation. Transmission electron microscopy showed massive collagen deposition. Immunostaining identified collagen IV as responsible for the increased thickness. Morphometry allowed the demonstration of a significant difference of thickness between control and exposed groups. Vascular alterations included: i) intima proliferation and thickening, rupture of the internal elastic lamina, thrombotic changes; ii) thickening of the media; iii) after 9 weeks of LFN-exposure, we found new formed vessel presenting tortuous and twisted. There is a significant difference of arterial wall thickness between control and exposed groups. CONCLUSIONS: Deeper layers of gastric wall undergo alterations, including fibrosis of the submucosa caused by collagen IV deposition, an early marker of neoangiogenesis. Vascular alterations included thickening and thrombotic phenomena, but also images of newly formed vessels. This study suggests that, at least in the stomach, LFN-induced fibrosis could be linked with neoangiogenesis.

scholarly journals The Degeneration of the Vestibular Efferent Neurons After Intratympanic Gentamicin Administration

2018 ◽  
Vol 66 (11) ◽  
pp. 801-812 ◽  
Author(s):  
Qianru Wu ◽  
Yibo Zhang ◽  
Chunfu Dai ◽  
Yu Kong ◽  
Lijun Pan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Choline Acetyltransferase ◽  
Underlying Mechanism ◽  
Vestibular Compensation ◽  
Control Group ◽  
Intratympanic Gentamicin ◽  
Transmission Electron ◽  
Significant Difference ◽  
Efferent Neurons

Intratympanic gentamicin (ITG) has been used to treat refractory Ménière’s disease. Disequilibrium after ITG was still a challenge for some patients, and the underlying mechanism is poorly understood. Our previous study demonstrated that gentamicin distributed in the bilateral vestibular efferent neurons (VEN) after ITG; however, does it lead to VEN damage and cause further disequilibrium in patients following ITG? In this study, we observed severe damaged gentamicin-positive neurons of VEN and severe fractured myelin layer plates around neural fibers when viewed under transmission electron microscopy at day 3 after ITG. At day 30, neurons of VEN presented with relatively normal structures. Compared with the control group, the total number of choline acetyltransferase (CHAT) immunolabeling neurons in bilateral VEN showed a significant decrease both at day 3 and day 30. However, there was no significant difference in the total number of CHAT immunolabeling neurons between day 3 and day 30. It indicates that gentamicin is not only retrogradely transported into bilateral VEN, but also results in the degeneration of VEN after ITG. These findings may be related to patients’ disequilibrium symptom after ITG. Furthermore, we speculate that VEN may play a role in vestibular compensation.

Oxide scale behavior of Al–7.5 mass%Mg alloy containing trace Ca during short-term oxidation

2021 ◽  
Vol 11 (11) ◽  
pp. 1881-1886
Author(s):  
Seong-Ho Ha ◽  
Young-Ok Yoon ◽  
Bong-Hwan Kim ◽  
Hyun-Kyu Lim ◽  
Sung-Hwan Lim ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Oxide Film ◽  
Phase Diagrams ◽  
Film Formation ◽  
Mg Alloy ◽  
Short Term ◽  
Spinel Formation ◽  
Transmission Electron ◽  
Significant Difference

In this study, using transmission electron microscopy and phase diagrams from thermodynamic calculations, we investigated the oxide film formation of Al–7.5 mass%Mg alloy containing Ca traces during short-term oxidation in terms of the thermodynamic stability and multi-element oxides by inter-diffusion based on the results of analysis for the oxide film. For the oxidation test at 515 ˚C, for 1 h, its results showed that there is no significant difference between the Ca-added and Ca-free Al–7.5 mass%Mg alloys was observed, while further exposure caused the Ca-free alloy to gain significant weight. Based on the standard Gibbs free energy for oxide production calculated in this study, CaO was the most preferential product among the single metal oxides examined. As per calculations for MgAl2O4-spinel formation reactions, the spinel formation from MgO was thermodynamically the most favorable. According to the phase diagrams calculated in this study, various multi-element oxides including Ca could possibly form in the oxide layer of Ca-added alloy. The analysis results of transmission electron microscopy confirmed that MgO is the primary oxide in the Al–Mg binary alloys. In oxidation tests conducted for less than 1 h, the spinel was rarely found. The outmost areas of oxide layers correspond to MgO and CaO in Ca-free and Ca-added alloys, respectively. However, in the Ca-added alloy, the inner layer contains certain amounts of Ca, Al, and Mg.

scholarly journals Effect of Chaihu Shugan Powder-Contained Serum on Glutamate-Induced Autophagy of Interstitial Cells of Cajal in the Rat Gastric Antrum

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Ren-Qian Tan ◽  
Zhi Zhang ◽  
Jing Ju ◽  
Jiang-Hong Ling
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Interstitial Cells Of Cajal ◽  
Underlying Mechanism ◽  
Control Group ◽  
Motility Disorders ◽  
Transmission Electron ◽  
Cells Of Cajal ◽  
Bcl2 Expression ◽  
Gi Motility

Gastrointestinal (GI) motility disorder is caused by excessive autophagy of the interstitial cells of Cajal (ICC). Chaihu Shugan Powder (CSP) is a traditional Chinese medicine with therapeutic benefits in GI motility disorders; however, the underlying mechanism of its therapeutic effect in GI disorders, especially autophagy of ICC, remains unclear. Thus, this study investigated the effects of CSP-contained serum on glutamate-induced autophagy in rat gastric ICC, exploring its underlying mechanism. In vitro cultured rat stomach ICC were identified by fluorescence microscopy and then stimulated with glutamate (5 mmol/L) for 3 h to establish the autophagy model. These cells were then treated with 10% CSP-containing serum or the autophagy inhibitor 3-methyladenine (3-MA; 5 mmol/L) for 24 h. The control group was cultured with only 10% serum containing physiological saline. The viability of ICC was measured by the CCK-8 assay. The ultrastructure and autophagosomes of ICC were observed using transmission electron microscopy. LC3 expression was detected by immunofluorescence, and LC3, Beclin1, Bcl2, and PI3KC3 expression was detected by western blot analysis. Transmission electron microscopy showed abundant endoplasmic reticulum, mitochondria, and other organelles in the control group, whereas the cells in the autophagy model control group had clear autophagic vacuoles, which were not apparent in both CSP and 3-MA groups. ICC viability was significantly increased by CSP and 3-MA interventions (P < 0.01), accompanied by a decrease in LC3 fluorescence (P < 0.01). Moreover, the expression levels of LC3II/I, Beclin1, and PI3KC3 were significantly decreased (all P < 0.01) with CSP and 3-MA treatment, while Bcl2 expression level was higher than that of the model group (P < 0.01). Thus, CSP can reduce autophagic damage by enhancing Bcl2 expression and downregulating the expression of LC3, Beclin1, and PI3KC3 to protect ICC. These results highlight the potential of CSP in the treatment of GI motility disorders.

scholarly journals Biodegradable PTLGA Terpolymers versus Collagen Implants Used as an Adjuvant in Trabeculectomy in Rabbit Eye

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Weiran Niu ◽  
Guanglin Shen ◽  
Yuanzhi Yuan ◽  
Xiaoping Ma ◽  
Suming Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ultrasound Biomicroscopy ◽  
Filtering Surgery ◽  
Trimethylene Carbonate ◽  
Rabbit Eye ◽  
Surgical Tool ◽  
Transmission Electron ◽  
Significant Difference ◽  
Versus Collagen

Purpose. To evaluate the effectiveness and safety of three biodegradable terpolymers prepared from L-lactide, trimethylene carbonate, and glycolide (PTLGA) as an aid for trabeculectomy compared with the Ologen (OLO).Methods. Trabeculectomy was carried out on rabbits with implantation made from OLO or three PTLGA terpolymers. Intraocular pressure (IOP) was recorded 1, 2, 3, and 6 months postoperatively and bleb evaluations were performed using ultrasound biomicroscopy (UBM) 3 months after surgery, optical coherence tomography (OCT) every month, and transmission electron microscopy (TEM) six months after surgery followed by histological examination 1, 2, 3, and 6 months postoperatively.Result. IOP was significantly reduced in all groups after surgery. There were no significant differences in the IOL between groups at any time after implantation. There was no significant difference between the groups examined by OCT, UBM, and TEM. Exposure of the implant was observed in one eye from the OLO group and one eye in the P1. Subconjunctiva hyperblastosis was observed in one eye from group P3 and two eyes from the OLO group.Conclusions. Subconjunctival implantation of filtering devices made from PTLGA may present a safe and effective additional surgical tool for the treatment of filtering surgery. Fewer complications were observed in the group with P2 implants compared to other groups.

scholarly journals The Effects of Riluzole on Cisplatin-induced Ototoxicity

2019 ◽  
Vol 23 (03) ◽  
pp. e267-e275 ◽  
Author(s):  
Selin Üstün Bezgin ◽  
Kadir Kemal Uygur ◽  
Çağıl Gökdoğan ◽  
Çiğdem Elmas ◽  
Güleser Göktaş
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Protective Effect ◽  
Guinea Pigs ◽  
Neuronal Cell ◽  
Auditory Brainstem ◽  
Auditory Brainstem Responses ◽  
Transmission Electron ◽  
Significant Difference ◽  
Brainstem Response

Introduction Riluzole (2-amino-6-trifluoromethoxy benzothiazole) is known as a neuroprotective, antioxidant, antiapoptotic agent. It may have beneficial effects on neuronal cell death due to cisplatin-induced ototoxicity. Objective To evaluate the effect of riluzole on cisplatin-induced ototoxicity in guinea pigs. Methods Twenty-four guinea pigs, studied in three groups, underwent auditory brainstem response evaluation using click and 8 kHz tone burst stimuli. Subsequently, 5 mg/kg of cisplatin were administered to all animals for 3 days intraperitoneally (i.p.) to induce ototoxicity. Half an hour prior to cisplatin, groups 1, 2 and 3 received 2 ml of saline i.p., 6 mg/kg of riluzole hydrochloride i.p., and 8 mg/kg of riluzole hydrochloride i.p., respectively, for 3 days. The auditory brainstem responses were repeated 24 hours after the last drug administration. The cochleae were analyzed by transmission electron microscopy (TEM). Results After drug administiration, for 8,000 Hz stimulus, group 1 had significantly higher threshold shifts when compared with groups 2 (p < 0.05) and 3 (p < 0.05), and there was no significant difference in threshold shifts between groups 2 and 3 (p > 0.05). Transmission electron microscopy findings demonstrated the protective effect of riluzole on the hair cells and the stria vascularis, especially in the group treated with 8 mg/kg of riluzole hydrochloride. Conclusion We can say that riluzole may have a protective effect on cisplatin- induced ototoxicity. However, additional studies are needed to confirm these results and the mechanisms of action of riluzole.

scholarly journals PM2.5 Exposure in the Respiratory System Induces Distinct Inflammatory Signaling in the Lung and the Liver of Mice

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Soi Jeong ◽  
Sang A Park ◽  
Inwon Park ◽  
Pilhan Kim ◽  
Nam Hoon Cho ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Mrna Expression ◽  
Immune Cells ◽  
Histological Analysis ◽  
Intravital Imaging ◽  
Two Photon ◽  
Transmission Electron ◽  
Significant Difference ◽  
Pm2.5 Exposure

Fine particulate matter 2.5 (PM2.5) is a harmful air pollutant currently threatening public health. Although many studies have been performed on the general negative effects of PM2.5 in mice and humans, the migration patterns of various immune cells in response to PM2.5 exposure remain unclear. In this study, we aimed to investigate the immune cell migratory response in the lung and the liver of intratracheally PM2.5-inoculated mice. To investigate the migration trajectory of immune cells in the lung and the liver tissues of mice, we employed microscopic tools including two-photon intravital imaging, histological analysis, and transmission electron microscopy. Our data from two-photon intravital imaging showed that there was no significant difference in the number of infiltrated neutrophils in the lung and the liver of PM2.5-treated mice, compared to the nontreated condition. However, from the histological analysis and the transmission electron microscopy after vascular perfusion to remove intravascular leukocytes, we observed that some leukocytes were frequently observed in the lung and the liver of PM2.5-treated mice. Interestingly, quantification of leukocyte population using flow cytometry showed significant increase of neutrophils and macrophages in the lung, but not much in the liver, 24 h post-PM2.5 treatment. These data imply that two-photon intravital imaging of the lung and the liver actually visualized neutrophils, which were adherent to the luminal side of the vasculature. We then conducted mRNA microarray analysis to further observe how PM2.5 affects gene expression patterns in the lung and the liver. PM2.5 treatment changed the mRNA expression associated with the IL-17 signaling pathway in the lung and changed the mRNA expression associated with metabolic pathways in the liver. In summary, these results suggest that the immune response in the lung is distinctly regulated from that in the liver under acute PM2.5-induced inflammation and that these organs consequently are regulated via distinct signaling pathways.

Effect of the Radioprotector WR2721 on Irradiation-Induced Injury to Ciliated Cells of Eustachian Tube

1992 ◽  
Vol 101 (5) ◽  
pp. 395-402 ◽  
Author(s):  
Timothy T. K. Jung ◽  
Young Min Park ◽  
David Panossian ◽  
Douglas Weeks ◽  
Stanley K. Miller ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Eustachian Tube ◽  
Control Group ◽  
Ciliated Cells ◽  
Transmission Electron ◽  
Irradiation Injury ◽  
Intraperitoneal Dose ◽  
Serous Otitis Media ◽  
Experimental Group

Our previous studies revealed that injury to the ciliated cells of the eustachian tube may be the primary cause of irradiation-induced serous otitis media. The purpose of this study was to investigate the effects of the radioprotector WR2721 on irradiation-induced injury to ciliated cells of the eustachian tube (ET) in chinchillas. Twelve chinchillas were divided into two groups: the control group and the experimental group, which was pretreated with a single intraperitoneal dose of the radioprotector S-2-[3-aminopropylamino]ethylphosphorothioic acid (WR2721) 400 mg/kg. The two groups were exposed to 30 Gy of 13-MeV electrons in a single fraction to the area of the bullae and nasopharynx. Ciliary dysfunction was tested and ciliated cells of the ET were examined by scanning and transmission electron microscopy. Pretreatment with WR2721 was found to protect ciliated cells of the ET from irradiation injury.

scholarly journals Characterization of light-absorbing carbon particles at three altitudes in East Asian outflow by transmission electron microscopy

2013 ◽  
Vol 13 (13) ◽  
pp. 6359-6371 ◽  
Author(s):  
J. Zhu ◽  
P. A. Crozier ◽  
J. R. Anderson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Size Fraction ◽  
Relative Number ◽  
The Yellow Sea ◽  
High Concentration ◽  
Carbonaceous Particles ◽  
Carbon Particles ◽  
Transmission Electron ◽  
Significant Difference

Abstract. The morphology, microstructure, and composition of the submicron fraction of individual light-absorbing carbon (LAC) particles collected by research aircraft during the ACE-Asia (Asian Pacific Regional Aerosol Characterization Experiment) project above the Yellow Sea at altitudes of 120, 450 and 1500 m are investigated by transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDS). Two types of carbonaceous particles, small spherule soot with graphitic spherules and amorphous carbonaceous spheres (brown carbon), are found at all altitudes in high concentration. For soot particles, emphasis of the study is on the component subparticles (spherules). The nanoscopic structures of the small spherule soot show no significant difference at three altitudes although the size distribution of primary spherules showed that 70% of the total volume lies in the ranges 30–50, 50–85 and 30–50 nm, respectively. For the amorphous carbonaceous spheres, 70% of the total volume from three altitudes lies in the range 200–350, 160–470 and 150–320 nm, respectively. Within the size fraction studied (submicron, with most particles in the range 50 to 500 nm) the number concentration ratios of the amorphous carbonaceous spheres to primary spherules in soot at altitudes of 120, 450 and 1500 m are about 1, 1.5 and 10, respectively and their volume ratios are about 260, 50 and 1400. Lower relative concentrations of large spherule soot with intermediate graphitic structure were observed at 120 m. Also, low relative number concentrations of carbon cenospheres were observed at 120 and 1500 m. A key result of the study is that in vertically stratified outflow from East Asia, the character of LAC may have strong variance with altitude thus resulting in optical characteristics that vary with altitude. Also, apparent "aging" of LAC deduced from samples at multiple ground stations may instead reflect differences in the original carbon aerosols.

The Influence of the ECAP Temperature on Microstructure and Mechanical Properties of a Magnesium Alloy

2006 ◽  
Vol 503-504 ◽  
pp. 609-614 ◽  
Author(s):  
Olya B. Kulyasova ◽  
Rinat K. Islamgaliev ◽  
Nikolay A. Krasilnikov
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Thermal Stability ◽  
Transmission Electron Microscopy ◽  
Magnesium Alloy ◽  
Volume Fraction ◽  
Angular Pressing ◽  
Transmission Electron ◽  
Significant Difference ◽  
Thermal Stability Of

The influence of the equal channel angular pressing (ECAP) temperature (150-350oC) on microstructure of the AM60 magnesium alloy has been investigated using transmission electron microscopy. It was demonstrated that application of various ECAP regimes leads to significant difference in a grain size and volume fraction of precipitates in investigated material. Thermal stability of precipitates and correlation between microstructure and tensile strength are discussed.

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