Novel Antiseptic Urinary Catheters for Prevention of Urinary Tract Infections: Correlation of In Vivo and In Vitro Test Results

ABSTRACT Urinary catheters are widely used for hospitalized patients and are often associated with high rates of urinary tract infection. We evaluated in vitro the antiadherence activity of a novel antiseptic Gendine-coated urinary catheter against several multidrug-resistant bacteria. Gendine-coated urinary catheters were compared to silver hydrogel-coated Foley catheters and uncoated catheters. Bacterial biofilm formation was assessed by quantitative culture and scanning electron microscopy. These data were further correlated to an in vivo rabbit model. We challenged 31 rabbits daily for 4 days by inoculating the urethral meatus with 1.0 × 109 CFU streptomycin-resistant Escherichia coli per day. In vitro, Gendine-coated urinary catheters reduced the CFU of all organisms tested for biofilm adherence compared with uncoated and silver hydrogel-coated catheters (P < 0.004). Scanning electron microscopy analysis showed that a thick biofilm overlaid the control catheter and the silver hydrogel-coated catheters but not the Gendine-coated urinary catheter. Similar results were found with the rabbit model. Bacteriuria was present in 60% of rabbits with uncoated catheters and 71% of those with silver hydrogel-coated catheters (P < 0.01) but not in those with Gendine-coated urinary catheters. No rabbits with Gendine-coated urinary catheters had invasive bladder infections. Histopathologic assessment revealed no differences in toxicity or staining. Gendine-coated urinary catheters were more efficacious in preventing catheter-associated colonization and urinary tract infections than were silver hydrogel-coated Foley catheters and uncoated catheters.

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

Cellular Physiology and Biochemistry ◽

10.1159/000493294 ◽

2018 ◽

Vol 49 (3) ◽

pp. 1151-1167 ◽

Cited By ~ 9

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.

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An Experimental Model for the Study of Venous Thrombosis in Vivo

10.1055/s-0039-1689660 ◽

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.

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

Infection and Immunity ◽

10.1128/iai.72.10.6023-6031.2004 ◽

2004 ◽

Vol 72 (10) ◽

pp. 6023-6031 ◽

Cited By ~ 244

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.

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

Parasites & Vectors ◽

10.1186/s13071-021-05065-x ◽

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

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Analysis of bovine oocytes maturated in vitro vs. in vivo by scanning electron microscopy

Theriogenology ◽

10.1016/0093-691x(96)84744-3 ◽

1996 ◽

Vol 45 (1) ◽

pp. 271 ◽

Cited By ~ 3

Author(s):

H. Suzuki ◽

G.A. Presicce ◽

X. Yang

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Bovine Oocytes ◽

Scanning Electron

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Structural Changes of Zona Pellucida Surface of Immature, In vivo and In Vitro Matured Canine Oocytes Using Scanning Electron Microscopy

Journal of Animal Reproduction and Biotechnology ◽

10.12750/jet.2018.33.4.281 ◽

2018 ◽

Vol 33 (4) ◽

pp. 281-286

Author(s):

Byung-Hyun Choi ◽

Ayman Mesalam ◽

Seok-Hwan Song ◽

Myeong-don Joo ◽

Ji-Yoon Hwang ◽

...

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Zona Pellucida ◽

Structural Changes ◽

Scanning Electron

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

Acta Scientiarum Biological Sciences ◽

10.4025/actascibiolsci.v43i1.57856 ◽

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.

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Zona pellucida birefringence correlates with developmental capacity of bovine oocytes classified by maturational environment, COC morphology and G6PDH activity

Reproduction Fertility and Development ◽

10.1071/rd11112 ◽

2012 ◽

Vol 24 (4) ◽

pp. 568 ◽

Cited By ~ 12

Author(s):

Eva Held ◽

Eva-Maria Mertens ◽

Abdollah Mohammadi-Sangcheshmeh ◽

Dessie Salilew-Wondim ◽

Urban Besenfelder ◽

...

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Zona Pellucida ◽

In Vitro Maturation ◽

Immature Oocytes ◽

Developmental Capacity ◽

Bovine Oocytes ◽

Scanning Electron

In the present study we aimed to analyse structural changes during in vitro maturation of the bovine zona pellucida (ZP) by scanning electron microscopy (SEM) ands zona pellucida birefringence (ZPB). Here we show that alterations during in vitro maturation invasively analysed by SEM are reflected in ZPB. In vivo-matured oocytes displayed significantly lower birefringence parameters and significantly higher blastocyst rates compared with in vitro-derived oocytes (39.1% vs 21.6%). The same was observed for in vitro-matured oocytes with cumulus–oocyte complex (COC) Quality 1 (Q1) compared with Q3-COCs with respect to zona birefringence and developmental capacity. Immature oocytes with Q1-COCs displayed higher ZPB values and a higher developmental capacity to the blastocyst stage (27.7% vs 16.9%) compared with immature Q3-COCs. Considering in vitro-matured oocytes, only those with Q1-COC showed a trend for ZPB similar to in vivo-matured oocytes. Therefore, a decreasing trend for ZPB during in vitro maturation seems to be typical for high-quality oocytes and successful cytoplasmic maturation. In accordance, fully-grown immature oocytes reached significantly higher blastocyst rates (32.0% vs 11.5%) and lower ZPB values compared with still-growing ones. In conclusion, we successfully evaluated the applicability of zona imaging to bovine oocytes: alterations during in vitro maturation invasively analysed by scanning electron microscopy were reflected in the birefringence of the zona pellucida of bovine oocytes affecting developmental capacity at the same value. Therefore ZPB measurement by live zona imaging has potential to become a new tool to assess correctness of in vitro maturation and to predict developmental competence.

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