Histomorphometry of Howship's lacunae formed in vivo and in vitro: Depths and volumes measured by scanning electron and confocal microscopy

Bone ◽  
1993 ◽  
Vol 14 (3) ◽  
pp. 455-460 ◽  
Author(s):  
S.J. Jones ◽  
A. Boyde
Keyword(s):  
Confocal Microscopy ◽  
Scanning Electron

scholarly journals Electrodeposited Platinum Iridium Enables Microstimulation With Carbon Fiber Electrodes

2021 ◽  
Vol 3 ◽  
Author(s):  
Elena della Valle ◽  
Beomseo Koo ◽  
Paras R. Patel ◽  
Quentin Whitsitt ◽  
Erin K. Purcell ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Cross Sections ◽  
Minimal Scarring ◽  
Pulse Testing ◽  
Implant Tests ◽  
Before And After ◽  
Voltage Transients ◽  
Scanning Electron

Ultrasmall microelectrode arrays have the potential to improve the spatial resolution of microstimulation. Carbon fiber (CF) microelectrodes with cross-sections of less than 8 μm have been demonstrated to penetrate cortical tissue and evoke minimal scarring in chronic implant tests. In this study, we investigate the stability and performance of neural stimulation electrodes comprised of electrodeposited platinum-iridium (PtIr) on carbon fibers. We conducted pulse testing and characterized charge injection in vitro and recorded voltage transients in vitro and in vivo. Standard electrochemical measurements (impedance spectroscopy and cyclic voltammetry) and visual inspection (scanning electron microscopy) were used to assess changes due to pulsing. Similar to other studies, the application of pulses caused a decrease in impedance and a reduction in voltage transients, but analysis of the impedance data suggests that these changes are due to surface modification and not permanent changes to the electrode. Comparison of scanning electron microscope images before and after pulse testing confirmed electrode stability.

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 Association of Lactobacillus spp. with Peyer's Patches in Mice

2001 ◽  
Vol 8 (2) ◽  
pp. 320-324 ◽  
Author(s):  
Laura Plant ◽  
Patricia Conway
Keyword(s):  
Peyer's Patches ◽  
Peyer’S Patches ◽  
Adhesion Assay ◽  
Scanning Electron Micrographs ◽  
Intestinal Tissue ◽  
High Adhesion ◽  
Preferential Binding ◽  
Scanning Electron

ABSTRACT Sixteen strains of Lactobacillus isolated from humans, mice, and food products were screened for their capacity to associate with Peyer's patches in mice. In preliminary experiments, in vitro binding to tissue pieces was assessed by scanning electron microscopy, and it was demonstrated qualitatively that 5 of the 16 strains showed some affinity for the Peyer's patches, irrespective of their association with the nonlymphoid intestinal tissue. Lactobacillus fermentum KLD was selected for further study, since, in addition to its intrinsically high adhesion rate, this organism was found to exhibit a preferential binding to the follicle-associated epithelium of the Peyer's patches compared with its level of binding to the mucus-secreting regions of the small intestine. Quantitative assessment of scanning electron micrographs of tissue sections which had been incubated with L. fermentum KLD or a nonbinding control strain, Lactobacillus delbruckii subsp.bulgaricus, supported these observations, since a marked difference in adhesion was noted (P < 0.05). This preferential association of strain KLD with the Peyer's patches was also confirmed with radiolabeled lactobacilli incubated with intestinal tissue in the in vitro adhesion assay. Direct recovery of L. fermentum KLD from washed tissue following oral dosing of mice revealed a distinct association (P < 0.05) between this organism and the Peyer's patch tissue. In contrast, L. delbruckii subsp. bulgaricus showed negligible binding to both tissue types in both in vitro and in vivo adhesion assays. It was concluded that L. fermentum KLD bound preferentially to Peyer's patches of BALB/c mice.

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 Pop-Cola Acids and Tooth Erosion: AnIn Vitro,In Vivo, Electron-Microscopic, and Clinical Report

2010 ◽  
Vol 2010 ◽  
pp. 1-12 ◽  
Author(s):  
Amirfirooz Borjian ◽  
Claudia C. F. Ferrari ◽  
Antoni Anouf ◽  
Louis Z. G. Touyz
Keyword(s):  
Clinical Case ◽  
Dental Erosion ◽  
Clinical Report ◽  
Tooth Erosion ◽  
Electron Microscopic ◽  
Ph Buffering ◽  
Wisdom Teeth ◽  
Scanning Electron

Introduction. Manufactured Colas are consumed universally as soft drinks. Evidence about the acid contents of Cola-beverages and its effects on teeth is rare.Aim. To assess (i) cola acidity and buffering capacityin vitro, (ii) tooth erosion after swishing with colasin vivo(iii) scanning electronmicroscopic effectson teeth of colas, and tooth-brush abrasion, and (iv) report aclinical caseof erosion from cola consumption.Materials and Methods. (i) We measured six commercially available pop “Cola beverages”, pH, and buffering capacities using a pH-Mettler Automatic Titrator, with weak solution of Sodium Hydroxide (ii) two cohorts, onewith teeth, the secondwithout teethrinsed with aliquots of Cola for 60 seconds. Swished cola samples tested for calcium and phosphorus contents using standardized chemical analytical methods (iii) enamel, dentine, and the enamel-cemental junction from unerupted extracted wisdom teeth were examined with a scanning electron microscope after exposure to colas, and tested for tooth-brush abrasion; (iv) a clinical case of pop cola erosion presentation, are all described.Results. Comparisons among pop colas testedin vitroreveal high acidity with very low pH. Buffering capacities in millilitres of 0.5 M NaOH needed to increase one pH unit, to pH 5.5 and pH 7 are reported. Rinsingin vivowith pop cola causes leeching of calcium from teeth; SEM shows dental erosion, and pop-cola consumption induces advanced dental erosion and facilitates abrasion.Conclusions. (i) Pop-Cola acid activity is below the critical pH 5.5 for tooth dissolution, with high buffering capacities countering neutralization effects of saliva; (ii) calcium is leeched out of teeth after rinsing with pop colas; (iii) SEM evidence explains why chronic exposure to acid pop colas causes dental frangibles; (iv) aclinical caseof pop-cola erosion confirms this.

scholarly journals Formulation and Evaluation of Ethyl Cellulose Based Fluconazole Nanosponges

2021 ◽  
pp. 135-145
Author(s):  
Jayadeep R. Yadav ◽  
Swati C. Jagdale ◽  
Anuruddha R. Chabukswar
Keyword(s):  
Ethyl Cellulose ◽  
Amorphous State ◽  
Skin Inflammation ◽  
Topical Administration ◽  
Systemic Absorption ◽  
In Vivo Experiments ◽  
Therapy Effectiveness ◽  
Scanning Electron

Background and Objective: Fluconazole (FLZ) is a novel triazole antifungistatic drug; topical administration of FLZ resulted in systemic absorption and skin inflammation, and thereby failed to achieve mycological eradication, resulting in low patient compliance and undermining therapy effectiveness. The aim of this study was to use the emulsion solvent evaporation technique to create FLZ-loaded nanosponges (NSs) using ethylcellulose (EC) and polyvinyl alcohol (PVA) as a stabiliser. Materials and Method: By varying the drug concentration (FLZ), EC, and PVA, four formulations were developed, each of which was then optimized through particle characterization (polydispersity index (PDI), scanning electron microscopy (SEM), zeta potential (ZP), drug entrapment, and loading efficiency). Results: SEM (Scanning Electron Microscope) analysis showed that the particle sizes of FLZ inclusion complexes ranged from 150 2 to 250 5 nm. The ZP was strong enough to produce stable formulations. FLZ was released from the nano sponges in a regulated manner for 24 hours in both in vitro and in vivo experiments. FTIR and DSC were used to validate the association of the FLZ with the nanosponges. The crystalline nature of FLZ was modified to an amorphous state due to the complexation with the nanosponges, according to an XRPD analysis. The FLZ nanosponges were found to be stable in a stability analysis. Conclusion: Therefore, ethyl cellulose-based nanosponges provide a novel method for controlling the release of FLZ for antifungal effects.

scholarly journals The use of confocal microscopy in experimental studies and clinical practice of an endocrinologist: modern opportunities

2019 ◽  
Vol 65 (3) ◽  
pp. 174-183
Author(s):  
Natalya G. Mokrysheva ◽  
Sergey L. Kiselev ◽  
Natalia V. Klementieva ◽  
Anna M. Gorbacheva ◽  
Ivan I. Dedov
Keyword(s):  
Confocal Microscopy ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Imaging Method ◽  
New Methods ◽  
Corneal Confocal Microscopy ◽  
Endocrine Ophthalmopathy ◽  
Fundamental Research

Confocal microscopy is a modern imaging method that provides ample opportunities for in vitro and in vivo research. The clinical part of the review focuses on well-established techniques, such as corneal confocal microscopy for the diagnosis of diabetic neuropathy or endocrine ophthalmopathy; new methods are briefly described (intraoperative evaluation of tissues obtained by removing pituitary adenomas, thyroid and parathyroid glands). In the part devoted to fundamental research, the use of confocal microscopy to characterize the colocalization of proteins, as well as three-dimensional intracellular structures and signaling pathways in vivo, is considered. Indicators of intracellular calcium are analyzed.

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 Adherence of enteroaggregative Escherichia coli to the ileal and colonic mucosa: an in vitro study utilizing the scanning electron microscopy

2011 ◽  
Vol 48 (3) ◽  
pp. 199-204 ◽  
Author(s):  
Jacy Alves Braga de Andrade ◽  
Edna Freymüller ◽  
Ulysses Fagundes-Neto
Keyword(s):  
Escherichia Coli ◽  
Organ Culture ◽  
Colonic Mucosa ◽  
In Vitro Study ◽  
In Vitro Assays ◽  
Electron Microscopic ◽  
In Vitro Organ Culture ◽  
Scanning Electron

CONTEXT: Enteroaggregative Escherichia coli strains have been associated with persistent diarrhea in several developing countries. In vivo procedures with animal models, in vitro assays with cellular lines and in vitro organ culture with intestinal fragments have been utilized to study these bacteria and their pathogenicity. OBJECTIVE: The present experimental research assessed the pathogenic interactions of three enteroaggregative Escherichia coli strains, using the in vitro organ culture, in order to show the adherence to different regions of both, the ileal and the colonic mucosa and demonstrate possible mechanisms that could have the participation in the prolongation of diarrheiogenic process. METHODS: This study used intestinal fragments from terminal ileum and colon that were excised from pediatric patients undergoing intestinal surgeries and from adult patients that underwent to colonoscopic procedures. Each strain was tested with three intestinal fragments for each region. Tissue was fixed for scanning electron microscopic analysis. RESULTS: These bacteria colonized ileal and colonic mucosa in the typical stacked-brick configuration in the ileum and colon. In both regions, the strains were seen over a great amount of mucus and sometimes over the intact epithelium. In some regions, there is a probable evidence of effacement of the microvilli. It was possible to see adhered to the intestinal surface, bacteria fimbrial structures that could be responsible for the adherence process. CONCLUSION: In order to cause diarrhea, enteroaggregative Escherichia coli strains adhere to the intestinal mucosa, create a mucoid biofilm on the small bowel surface that could justify the digestive-absorptive abnormalities and consequently, prolonging the diarrhea.

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