scholarly journals Preparation, Characterization, and Immuno-Enhancing Activity of Polysaccharides from Glycyrrhiza uralensis

Biomolecules ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 159 ◽  
Author(s):  
Adila Aipire ◽  
Pengfei Yuan ◽  
Alimu Aimaier ◽  
Shanshan Cai ◽  
Mahepali Mahabati ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Smooth Surface ◽  
Cytokine Production ◽  
Glycyrrhiza Uralensis ◽  
Molecular Weights ◽  
Chinese Herbal ◽  
Ft Ir ◽  
Scanning Electron

Glycyrrhiza uralensis is a Chinese herbal medicine with various bioactivities. Three fractions (GUPS-I, GUPS-II and GUPS-III) of G. uralensis polysaccharides (GUPS) were obtained with molecular weights of 1.06, 29.1, and 14.9 kDa, respectively. The monosaccharide compositions of GUPS-II and GUPS-III were similar, while that of GUPS-I was distinctively different. The results of scanning electron microscopy, FT-IR, and NMR suggested that GUPS-II and GUPS-III were flaky with a smooth surface and contained α- and β-glycosidic linkages, while GUPS-I was granulated and contained only α-glycosidic linkages. Moreover, GUPS-II and GUPS-III exhibited better bioactivities on the maturation and cytokine production of dendritic cells (DCs) in vitro than that of GUPS-I. An in vivo experiment showed that only GUPS-II significantly enhanced the maturation of DCs. These results indicate that GUPS-II has the potential to be used in combination with cancer immunotherapy to enhance the therapeutic effect.

scholarly journals Φασματοσκοπική μελέτη της επίδρασης των ακτινοβολιών στον ανθρώπινο αρθρικό χόνδρο

2016 ◽  
Author(s):  
Ανδρέας Μαυρογένης
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Ft Ir ◽  
Scanning Electron

Στην προύσα εργασία χρησιμοποιήθηκε η υπέρυθρη φασματοσκοπία με μετασχηματισμό Fourier σε συνδυασμό με οπτικό μικροσκόπιο υψηλή ανάλυσης και μικροσκόπιο διασποράς SEM (scanning electron microscopy) για την in vitro μελέτη της επίδρασης των ιοντιζουσών ακτινοβολιών στον αρθρικό χόνδρο, τη διεπιφάνεια με το οστούν, και για την προσέγγιση του χημικού μηχανισμού που προκαλείται κατά την ακτινοθεραπεία.Από τις μεταβολές των εντάσεων και τις νέες ταινίες στην περιοχή μεταξύ 4000-2800 cm-1, διαπιστώθηκε ότι οι βλάβες οι οποίες προκαλούνται σε μικρές δόσεις ακτινοβολίας μέχρι 6 Gy είναι οι σχάσεις των δεσμών υδρογόνου των γλυκοζαμινογλυκανών (πολυγλυκάνες, υαλουρονικό οξύ) και των κολλαγονούχων πρωτεϊνών.Τα θραύσματα του κολλαγόνου και υαλουρονικού οξέος αντιδρούν μεταξύ τους με διασταυρούμενο πολυμερισμό σχηματίζοντας προϊόντα στα οποία αποδίδεται η μείωση του ιξώδους των χόνδρων και επομένως η αύξηση της τριβής και τέλος η φθορά των χόνδρων. Τα αποτελέσματα αυτά επιβεβαιώθηκαν με σύγκριση ανάλογων χόνδρων οι οποίοι αφαιρέθηκαν από ασθενείς λόγω οστεοαρθρίτιδας ή άλλης αιτίας βλάβης του αρθρικού χόνδρου και καρκίνου.Οι μεταβολές στην περιοχή του φάσματος μεταξύ 1800-1400 cm-1, όπου εμφανίζονται οι χαρακτηριστικές δονήσεις των κολλαγονούχων πρωτεϊνών έδειξαν την καταστροφή της έλικας από α-έλικα, η οποία επικρατεί στην φυσιολογική κατάσταση, σε τυχαία περιέλιξη μετά την επίδραση των ιοντιζουσών ακτινοβολιών. Με αύξηση της δόσης ακτινοβολίας παράγονται αμυλοειδούς τύπου πρωτεΐνες από τα θραύσματα των πρωτεϊνών που παράγονται, λόγω της επίδρασης των ελευθέρων ριζών υδροξυλίου.Η εμφάνιση της ταινίας στα 1742 cm-1 αποδίδεται στην υπεροξείδωση των μεμβρανών των κυττάρων η οποία προκαλείται από την παρουσία του οξυγόνου, το οποίο, ως ελεύθερη δίριζα συμβάλλει στην περαιτέρω καταστροφή των ιοντιζουσών ακτινοβολιών. Η ταινία χαρακτηρίζει τον σχηματισμό μαλονδιαλδεΰδης, μία ένωση που αποτελεί δείκτη για την εξέλιξη της ασθένειας.Από τις ταινίες στην περιοχή του φάσματος μεταξύ 1400-900 cm-1 όπου εμφανίζονται οι χαρακτηριστικές δονήσεις των ομάδων –C-O-C- των σακχάρων διαπιστώνεται η αύξηση των D-σακχάρων, τα οποία προκύπτουν από την αύξηση των μονομερών. Οι εντάσεις των ταινιών αυτών εξαρτώνται από τη δόση ακτινοβολίας και αυξάνει αναλογικά μέχρι δόσεις περίπου 9 Gy. Πέραν αυτής της δόσης, οι παραγόμενες ελεύθερες ρίζες αντιδρούν περαιτέρω με βασικά βιομόρια και μεταβάλλουν την τοξική επίδραση της ακτινοβολίας.Στην περιοχή μεταξύ 1300-900 cm-1, οι ταινίες του φάσματος των σακχάρων συνυπάρχουν με τις ταινίες των φωσφορικών αλάτων του υδροξυαπατίτη των οστών. Από την μορφή των ταινιών και τις θέσεις των μεγίστων απορρόφησης φαίνεται ο σχηματισμός άμορφου φωσφορικού ασβεστίου [Ca3(ΡΟ4)2] ο οποίος προέρχεται από την αντίδραση των ιόντων ασβεστίου (Ca2+) του υγρού των χόνδρων με τις φωσφορικές ομάδες των φωσφολιπιδίων των κυτταρικών μεμβρανών.Τα FT-IR φάσματα συγκρίθηκαν με φάσματα ασθενών με οστεοαρθρίτιδα και διαπιστώθηκε ότι τα φάσματα παρουσιάζουν ομοιότητες, οι οποίες ερμηνεύονται με μηχανισμούς ελευθέρων ριζών.Η μελέτη της αρχιτεκτονικής των χόνδρων με οπτικό μικροσκόπιο και ηλεκτρονικό μικροσκόπιο σάρωσης (SEM) έδειξαν ότι η φθορά την οποία προκαλούν οι ιοντίζουσες ακτινοβολίες είναι ίδια με αυτή που προκαλεί η φυσιολογική γήρανση του ατόμου και εκδήλωση οστεοαρθρίτιδας.Τα δεδομένα της μελέτης δείχνουν ότι οι ιοντίζουσες ακτινοβολίες κατά την ακτινοθεραπεία προκαλούν σχάση των αλυσίδων των γλυκοζαμικογλυκανών και κολλαγονούχων πρωτεϊνών, οι οποίες οδηγούν σε μη αντιστρεπτές βλάβες. Οι παρατηρήσεις αυτές δείχνουν ότι θα πρέπει να αναπτυχθεί νέα σειρά θεραπευτικού σχήματος για την αντιμετώπιση των βλαβών, οι οποίες προκαλούνται στα υγιή κύτταρα τα οποία ακτινοβολούνται παράλληλα με τα παθολογικά.

scholarly journals Low-Level Aflatoxin B1 Promotes Influenza Infection and Modulates a Switch in Macrophage Polarization from M1 to M2

2018 ◽  
Vol 49 (3) ◽  
pp. 1151-1167 ◽  
Author(s):  
Yuhang Sun ◽  
Zixuan Liu ◽  
Dandan Liu ◽  
Jin Chen ◽  
Fang Gan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Influenza Virus ◽  
Matrix Protein ◽  
Macrophage Polarization ◽  
Low Level ◽  
Siv Infection ◽  
Scanning Electron

Background/Aims: Swine influenza virus (SIV) is a major pathogen of both animals and humans. Afatoxin B1 (AFB1) is one of the most common mycotoxins in feed and food. However, the central contribution of AFB1 to SIV infection remains unclear. Methods: Here, TCID50 assays, fluorescence-based quantitative real-time PCR, western blotting, immunofluorescence staining, histopathological examination, flow cytometry and scanning electron microscopy were performed to investigate the involvement and underlying mechanism of AFB1 in SIV infection in vivo and in vitro using mouse models and porcine alveolar macrophage (PAM) models, respectively. Results: The in vivo study showed that low levels of AFB1 promoted SIV infection and increased its severity, as demonstrated by the increased mRNA expression of viral matrix protein (M); by the increased protein expression of nucleoprotein (NP), matrix protein 1 and ion channel protein; and by animal weight loss, lung index and lung histologic damage. In addition, the increased occurrence of SIV infection accompanied by increases in the level of IL-10 in sera and lungs, in the spleen index and in the number of CD206-positive mouse alveolar macrophages but decreases in the level of TNF-α in sera and lungs, in the thymus index and in the number of CD80-positive mouse alveolar macrophages was observed in SIV-infected mice after low-level AFB1 exposure. The in vitro study showed that low concentrations of AFB1 promoted SIV infection, as demonstrated by the increases in viral titers and viral M mRNA and NP expression levels in SIV-infected PAMs as well as by the number of cells positive for NP protein expression. Furthermore, AFB1 promoted the polarization of SIV-infected PAMs to the M1 phenotype at 8 hpi and to the M2 phenotype at 24 hpi, as measured by the increases in IL-10 expression and in the number of CD206-positive PAMs as well as by the morphological changes observed by scanning electron microscopy. The administration of the immune stimulant lipopolysaccharide (LPS) reversed the switch in PAM polarization from M2 to M1 and thereby counteracted the promotion of influenza virus infection induced by AFB1. Conclusion: Our results are the first to confirm that low-level exposure to AFB1 promotes SIV infection and modulates a switch in macrophage polarization from M1 to M2. The work reported here provides important data that point to a role for AFB1 in SIV infection, and it opens a new field of study.

An Experimental Model for the Study of Venous Thrombosis in Vivo

1975 ◽  
Author(s):  
T. K. Day ◽  
K. G. A. Glark ◽  
V. V. Kakkar
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Experimental Model ◽  
Femoral Vein ◽  
Total Charge ◽  
Small Current ◽  
Group I ◽  
Scanning Electron

The lack of a satisfactory in vivo experimental model has probably been responsible for the delay in the clinical application of recent advances in in vitro research on thrombosis. This paper describes a model in which thrombosis is initiated by an electrical stimulus. The thrombus produced has the histological and biochemical features of human deep vein thrombosis (DVT).The minimum stimulus necessary to induce thrombosis was first determined by passing a fixed current for timed intervals along the femoral veins of 10 rabbits. Thrombi were seen 24 hours later if the total charge passed exceeded a threshold value of 25 millicoulombes. With this small current, no endothelial changes were visible immediately after the passage of the charge on light or scanning electron microscopy. At 24 hours a mural thrombus formed, which had fully cross-linked fibrin and histological features resembling human DVT.In the second series of experiments, the sequence of changes occurring in thrombus production was investigated in 3 groups of 18 rabbits each. After passage of the critical charge along the femoral vein in each animal, veins were removed at fixed intervals, the contralateral vein acting as a control. The veins were examined by scanning electron-microscopy (Group I), transmission electron-microscopy (Group II) and light microscopy (Group III), The earliest changes were detectable at 5 minutes and consisted of the laying down of an organised structure of criss-crossing fibrin strands with small platelet clumps at fibrin intersections. Later the fibrin structure spread towards the lumen; platelet clumps fused and a coralline thrombus was formed by 24 hours. The significance of these changes will be discussed.

scholarly journals Development and Characterization of an In Vivo Central Venous Catheter Candida albicans Biofilm Model

2004 ◽  
Vol 72 (10) ◽  
pp. 6023-6031 ◽  
Author(s):  
D. Andes ◽  
J. Nett ◽  
P. Oschel ◽  
R. Albrecht ◽  
K. Marchillo ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Drug Resistance ◽  
Venous Catheter ◽  
In Vitro Models ◽  
Central Venous ◽  
Biofilm Growth ◽  
Scanning Electron

ABSTRACT Biofilms represent a niche for microorganisms where they are protected from both the host immune system and antimicrobial therapies. Biofilm growth serves as an increasing source of clinical infections. Candida infections are difficult to manage due to their persistent nature and associated drug resistance. Observations made in biofilm research have generally been limited to in vitro models. Using a rat central venous catheter model, we characterized in vivo Candida albicans biofilm development. Time-course quantitative culture demonstrated a progressive increase in the burden of viable cells for the first 24 h of development. Fluorescence and scanning electron microscopy revealed a bilayered architecture. Adjacent to the catheter surface, yeast cells were densely embedded in an extracellular matrix. The layer adjacent to the catheter lumen was less dense. The outermost surface of the biofilm contained both yeast and hyphal forms, and the extracellular material in which they were embedded appeared fibrous. These architectural features were similar in many respects to those described for in vitro models. However, scanning electron microscopy also revealed host cells embedded within the biofilm matrix. Drug susceptibility was determined by using two assays and demonstrated a biofilm-associated drug resistance phenotype. The first assay demonstrated continued growth of cells in the presence of supra-MIC antifungal drug concentrations. The second assay demonstrated reduced susceptibility of biofilm-grown cells following removal from the biofilm structure. Lastly, the model provided sufficient nucleic material for study of differential gene expression associated with in vivo biofilm growth. Two fluconazole efflux pumps, CDR1 and CDR2, were upregulated in the in vivo biofilm-associated cells. Most importantly, the studies described provide a model for further investigation into the molecular mechanisms of C. albicans biofilm biology and drug resistance. In addition, the model provides a means to study novel drug therapies and device technologies targeted to the control of biofilm-associated infections.

scholarly journals Radicicol, a Novel Lead Compound against the Migratory-Stage Schistosomula of Schistosoma japonicum

2020 ◽  
Vol 65 (3) ◽  
Author(s):  
Liangxiong Xu ◽  
Qiuli Liu ◽  
Qingren Zeng ◽  
Ping Wu ◽  
Quan Yu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Schistosoma Japonicum ◽  
Primary Treatment ◽  
Parasitic Disease ◽  
Lead Compound ◽  
Content Type ◽  
Acid Lactone ◽  
Scanning Electron

ABSTRACT Schistosomiasis poses a serious threat to human health and remains a major tropical and parasitic disease in more than 70 countries. Praziquantel (PZQ) has been the primary treatment for schistosomiasis for nearly 4 decades. However, its efficacy against migratory-stage schistosomula is limited. Radicicol (RAD), a β-resorcylic acid lactone derived from Paecilomyces sp. strain SC0924, was investigated as an alternative treatment for Schistosoma japonicum. In vitro tests showed that within 72 h, RAD (10 μmol/liter) completely killed schistosomula of both skin and liver stages with an efficacy significantly higher than that of PZQ, although it was less potent against adult worms than PZQ. In vivo, RAD reduced worm burdens and liver eggs by 91.18% and 86.01%, respectively, by killing migratory-stage schistosomula. Optical microscopy and scanning electron microscopy revealed that RAD damaged the epiderm and tegument morphology of S. japonicum worms at various stages and altered their motility to different degrees. RAD exhibited schistosomicidal effects at different stages in vitro and in vivo, especially at the migratory stage, implying that its mechanism could be different from that of PZQ. Collectively, these results showed that RAD is promising as a lead for the development of drugs to control the migratory-stage schistosomula of S. japonicum.

scholarly journals Synergistic effect of combination chemotherapy with praziquantel and DW-3-15 for Schistosoma japonicum in vitro and in vivo

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Zi-Yin Yang ◽  
Zi-Hao Liu ◽  
Ya-Nan Zhang ◽  
Chen Li ◽  
Lei Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Synergistic Effect ◽  
Schistosoma Japonicum ◽  
Combination Chemotherapy ◽  
Combination Index ◽  
First Choice ◽  
Scanning Electron

Abstract Background Schistosomiasis is a debilitating and neglected tropical disease for which praziquantel (PZQ) remains the first-choice drug for treatment and control of the disease. In our previous studies, we found that the patented compound DW-3-15 (patent no. ZL201110142538.2) displayed significant and stabilized antiparasitic activity through a mechanism that might be distinct from PZQ. Here, we investigated the antischistosomal efficacy of PZQ combined with DW-3-15 against schistosomula and adult worms of Schistosoma japonicum in vitro and in vivo, to verify whether there was a synergistic effect of the two compounds. Methods The antischistosomal efficacy of PZQ combined with DW-3-15 in comparison with an untreated control and monotherapy group against schistosomula and adult worms was assessed both in vitro and in vivo. Parasitological studies, scanning electron microscopy, combination index, and histopathological analysis were used for the assessment. Results The results showed significantly reduced viability of schistosomes, achieving 100% viability reduction for juveniles and males by combination chemotherapy using PZQ together with DW-3-15 in vitro. The combination index was 0.28, 0.27, and 0.53 at the higher concentration of PZQ combined with DW-3-15 against juveniles, males, and females, respectively, indicating that the two compounds display strong synergism. Scanning electron microscopy observations also demonstrated that the compound combination induced more severe and extensive alterations to the tegument and subtegument of S. japonicum than those with each compound alone. In vivo, compared with the single-compound-treated group, the group treated with the higher-dose combination demonstrated the best schistosomicidal efficacy, with significantly reduced worm burden, egg burden, and granuloma count and area, which was evident against schistosomula and adult worms. Conclusions Our study provides a potential novel chemotherapy for schistosomiasis caused by S. japonicum. It would improve the antischistosomal effect on schistosomula and adult worms of S. japonicum, and decrease individual dosages. Graphical Abstract

Study of Morphology of Cardiac Valves (Human and Bovine Pericardium) after In Vivo Calcification

2008 ◽  
Vol 396-398 ◽  
pp. 191-194
Author(s):  
Grínia M. Nogueira ◽  
Cassiano Gomes Aimoli ◽  
Raquel Farias Weska ◽  
Adolfo A. Leirner ◽  
Marina J.S. Maizato ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Bovine Pericardium ◽  
Cardiac Valves ◽  
Elemental Analyses ◽  
Calcification Process ◽  
Pathologic Calcification ◽  
Phosphate Deposits ◽  
Scanning Electron

Pathologic calcification can lead to failure or deterioration of cardiac valves. Several researchers have tried alternatives to construct these devices, such as the incorporation or utilization of new biomaterials able to inhibit or decrease the calcification process. In vitro calcification tests can be used to screen new biomaterials regarding their potential to calcify in vivo. However, the mechanisms involved in both cases are not completely understood. In order to collect more information about the calcification process of implanted materials, morphology and elemental analyses of calcified cardiac valve fragments explanted from different patients were investigated and compared to previous reports of in vitro calcification tests. Scanning Electron Microscopy (SEM) and energy dispersive spectroscopy (EDS) analyses indicated that the calcium phosphate deposits from both bovine pericardium and human cardiac valves calcified in vivo were similar to the deposits obtained from in vitro calcification samples as previously reported in the literature.

scholarly journals In vitro and in vivo genotoxicity and cytotoxicity analysis of protein extract from Aplysina fulva sponges

2021 ◽  
Vol 43 ◽  
pp. e57856
Author(s):  
Alan de França Santana ◽  
Ingrid Regina Avanzi ◽  
Julia Risso Parisi ◽  
Matheus Almeida Cruz ◽  
Giovanna Caroline Aparecida do Vale ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Viability ◽  
Mass Loss ◽  
Morphological Properties ◽  
Protein Extract ◽  
Eds Analysis ◽  
Scanning Electron

This study evaluated the physicochemical and morphological properties of a marine sponge protein extract (PE) using scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDS), analysis of mass loss and pH and in vitro and in vivo. Scanning electron microscopy showed that PE fibers present a granular aspect and irregular structure and the element carbon followed by oxygen was detected in the EDS analysis. Moreover, a 29% of mass loss was observed after 14 days and the pH slightly modified after 14 days. Cell viability of fibroblast cells (L929) of control and PE at a concentration of 25% demonstrated higher values compared to the groups. Osteoblast cell viability of PE at 25 and 50% was significantly higher. Comet assay on day 1 showed higher values for PE at 25%. In addition, in vivo experiments demonstrated that in the treated animals, the bone defects were filled with biomaterial particles, granulation tissue and some areas of newly formed bone. Furthermore, similar immunoexpression of Runx-2 and Cox-2 was observed. Taken together, all results suggest that PE is biocompatible, present non-citotoxicity in the in vitro studies (at the lower concentration) and in the in vivo studies and it can be considered as an alternative source of collagen for tissue engineering proposals.

Sign in / Sign up

Export Citation Format

Share Document