Ultrastructure of the infection of spruce budworm larvae by the fungus Entomophaga aulicae

The infection of spruce budworm larvae by the fungus Entomophaga aulicae was studied by light, scanning, and transmission electron microscopy. Exposure of the larvae to conidia resulted in the death of the host and the production of a crop of infective conidia within 5 to 6 days. Germinating conidia produced appressoria prior to penetration of the larval cuticle. Nuclei in appressoria were larger and contained less heavily condensed chromatin than nuclei in other stages of fungal development. Attachment and infection were characterized by distinct changes in the wall layers of the fungus. An infection hypha grew through the insect tissues directly into the hemocoel where discontinuities were observed in the wall layers at the apex of the infection hypha. These discontinuities are probably associated with protoplast formation in vivo. Protoplasts with polysaccharide and lipid storage material were present in the hemolymph of larvae 3 days after exposure to conidia. Thick-walled hyphal bodies with abundant lipid reserve filled the larval body cavity by the 5th day. Hyphal bodies germinated to produce unbranched, aseptate conidiophores which emerged through the host cuticle prior to conidiogenesis.

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Pharmacokinetic Evaluation of 99mTc-radiolabeled Solid Lipid Nanoparticles and Chitosan Coated Solid Lipid Nanoparticles

Current Drug Metabolism ◽

10.2174/1389200220666191112145808 ◽

2020 ◽

Vol 20 (13) ◽

pp. 1044-1052

Author(s):

Nasrin Abbasi Gharibkandi ◽

Sajjad Molavipordanjani ◽

Jafar Akbari ◽

Seyed Jalal Hosseinimehr

Keyword(s):

Solid Lipid Nanoparticles ◽

Lipid Nanoparticles ◽

High Resistivity ◽

Scanning Calorimetry ◽

Liver Uptake ◽

Solid Lipid ◽

Transmission Electron ◽

Main Portion ◽

Pharmacokinetic Behavior

Background: Solid Lipid Nanoparticles (SLNs) possess unique in vivo features such as high resistivity, bioavailability, and habitation at the target site. Coating nanoparticles with polymers such as chitosan greatly affects their pharmacokinetic behavior, stability, tissue uptake, and controlled drug delivery. The aim of this study was to prepare and evaluate the biodistribution of 99mTc-labeled SLNs and chitosan modified SLNs in mice. Methods: 99mTc-oxine was prepared and utilized to radiolabel pre-papered SLNs or chitosan coated SLNs. After purification of radiolabeled SLNs (99mTc-SLNs) and radiolabeled chitosan-coated SLNs (99mTc-Chi-SLNs) using Amicon filter, they were injected into BALB/c mice to evaluate their biodistribution patterns. In addition, nanoparticles were characterized using Transmission Electron Microscopy (TEM), Fourier-transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), X-ray Powder Diffraction (XRD) and Dynamic Light Scattering (DLS). Results: 99mTc-oxine with high radiochemical purity (RCP~100%) and stability (RCP > 97% at 24 h) was used to provide 99mTc-SLNs and 99mTc-Chi-SLNs with high initial RCP (100%). TEM image and DLS data suggest 99mTc- SLNs susceptibility to aggregation. To that end, the main portion of 99mTc-SLNs radioactivity accumulates in the liver and intestines, while 99mTc-Chi-SLNs sequesters in the liver, intestines and kidneys. The blood radioactivity of 99mTc-Chi-SLNs was higher than that of 99mTc-SLNs by 7.5, 3.17 and 3.5 folds at 1, 4 and 8 h post-injection. 99mTc- Chi-SLNs uptake in the kidneys in comparison with 99mTc-SLNs was higher by 37.48, 5.84 and 11 folds at 1, 4 and 8h. Conclusion: The chitosan layer on the surface of 99mTc-Chi-SLNs reduces lipophilicity in comparison with 99mTc- SLNs. Therefore, 99mTc-Chi-SLNs are less susceptible to aggregation, which leads to their lower liver uptake and higher kidney uptake and blood concentration.

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Mice with cleavage-resistant N-cadherin exhibit synapse anomaly in the hippocampus and outperformance in spatial learning tasks

Molecular Brain ◽

10.1186/s13041-021-00738-1 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

M. Asada-Utsugi ◽

K. Uemura ◽

M. Kubota ◽

Y. Noda ◽

Y. Tashiro ◽

...

Keyword(s):

Memory Function ◽

Three Dimensional ◽

Excitatory Synapses ◽

Missense Mutations ◽

Glutamatergic Synapses ◽

Learning Tasks ◽

Transmission Electron ◽

Nmdar Activation ◽

And Function

AbstractN-cadherin is a homophilic cell adhesion molecule that stabilizes excitatory synapses, by connecting pre- and post-synaptic termini. Upon NMDA receptor (NMDAR) activation by glutamate, membrane-proximal domains of N-cadherin are cleaved serially by a-disintegrin-and-metalloprotease 10 (ADAM10) and then presenilin 1(PS1, catalytic subunit of the γ-secretase complex). To assess the physiological significance of the initial N-cadherin cleavage, we engineer the mouse genome to create a knock-in allele with tandem missense mutations in the mouse N-cadherin/Cadherin-2 gene (Cdh2R714G, I715D, or GD) that confers resistance on proteolysis by ADAM10 (GD mice). GD mice showed a better performance in the radial maze test, with significantly less revisiting errors after intervals of 30 and 300 s than WT, and a tendency for enhanced freezing in fear conditioning. Interestingly, GD mice reveal higher complexity in the tufts of thorny excrescence in the CA3 region of the hippocampus. Fine morphometry with serial section transmission electron microscopy (ssTEM) and three-dimensional (3D) reconstruction reveals significantly higher synaptic density, significantly smaller PSD area, and normal dendritic spine volume in GD mice. This knock-in mouse has provided in vivo evidence that ADAM10-mediated cleavage is a critical step in N-cadherin shedding and degradation and involved in the structure and function of glutamatergic synapses, which affect the memory function.

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Qualitative ultrastructural analysis of the submandibular salivary glands after administration of khat: in vivo study

BMC Research Notes ◽

10.1186/s13104-021-05595-8 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Gamilah Al-Qadhi ◽

Rabab Mubarak

Keyword(s):

Salivary Glands ◽

Arabian Peninsula ◽

Submandibular Salivary Gland ◽

Catha Edulis ◽

Ductal Cells ◽

Cytoplasmic Vacuoles ◽

Transmission Electron ◽

Salivary Gland Cells ◽

Submandibular Salivary Glands

Abstract Objective Khat (Catha edulis Forssk) plant has been widely chewed for its psychostimulatory effects in the African and Arabian Peninsula, particularly in Yemen. Considering the khat leaves are gradually chewed without swallowing, while its active constituents are extracted into saliva, studying the effect of khat on salivary glands is necessary. This work is an extension of the previously published work that studied the effect of khat extract on the rats' submandibular salivary glands in terms of histological and immunohistochemical evaluations. The current research note aimed to better understand this effect on the ultrastructure of submandibular salivary gland cells by using transmission electron microscope. Results Oral administration of khat extract produced degenerative changes in the secretory and ductal cells of rats' submandibular salivary glands. These changes involved irregular boundaries of variable sized-nuclei, dilated RER, cytoplasmic vacuoles as well as swollen and degenerated mitochondria.

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Cemp1-p3 Peptide Promotes the Transformation of Octacalcium Phosphate into Hydroxyapatite Crystals

Crystals ◽

10.3390/cryst10121131 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1131

Author(s):

Maricela Santana ◽

Gonzalo Montoya ◽

Raúl Herrera ◽

Lía Hoz ◽

Enrique Romo ◽

...

Keyword(s):

Electron Microscopy ◽

Octacalcium Phosphate ◽

Sequence Motifs ◽

Simple Method ◽

Transmission Electron ◽

Precursor Phase ◽

Mineralized Tissues ◽

Potent Growth

Dental cementum contains unique molecules that regulate the mineralization process in vitro and in vivo, such as cementum protein 1 (CEMP1). This protein possesses amino acid sequence motifs like the human recombinant CEMP1 with biological activity. This novel cementum protein 1-derived peptide (CEMP1-p3, from the CEMP1’s N-terminal domain: (QPLPKGCAAVKAEVGIPAPH), consists of 20 amino acids. Hydroxyapatite (HA) crystals could be obtained through the combination of the amorphous precursor phase and macromolecules such as proteins and peptides. We used a simple method to synthesize peptide/hydroxyapatite nanocomposites using OCP and CEMP1-p3. The characterization of the crystals through scanning electron microscopy (SEM), powder X-ray diffraction (XRD), high--resolution transmission electron microscopy (HRTEM), and Raman spectroscopy revealed that CEMP1-p3 transformed OCP into hydroxyapatite (HA) under constant ionic strength and in a buffered solution. CEMP1-p3 binds and highly adsorbs to OCP and is a potent growth stimulator of OCP crystals. CEMP1-p3 fosters the transformation of OCP into HA crystals with crystalline planes (300) and (004) that correspond to the cell of hexagonal HA. Octacalcium phosphate crystals treated with CEMP1-p3 grown in simulated physiological buffer acquired hexagonal arrangement corresponding to HA. These findings provide new insights into the potential application of CEMP1-p3 on possible biomimetic approaches to generate materials for the repair and regeneration of mineralized tissues, or restorative materials in the orthopedic field.

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A novel design of HA-coated nanoparticles co-encapsulating plasmid METase and 5-Fu shows enhanced application in targeting gastric cancer stem cells

Biological Chemistry ◽

10.1515/hsz-2017-0208 ◽

2018 ◽

Vol 399 (3) ◽

pp. 293-303 ◽

Cited By ~ 3

Author(s):

Weifeng Yang ◽

Houting Zhang ◽

Lin Xin

Keyword(s):

Gastric Cancer ◽

Tumor Growth ◽

Precipitation Method ◽

Inhibition Effect ◽

Coated Nanoparticles ◽

Transmission Electron ◽

Targeted Drug ◽

Gastric Cancer Stem Cells ◽

Novel Design

AbstractNanoparticles (NPs) are recognized as an attractive vehicles for cancer treatment due to their targeted drug release. Gastric cancer is an important killer disease, and its therapy methods still need improvement. The NPs were prepared using a precipitation method, and were evaluated using transmission electron microscopy (TEM). MTT and Transwell assays were used to determine cell viability and apoptosis.In vivoexperiments were performed to validate the effects of NPs on tumor growth. Methioninase (METase)/5-Fu co-encaspulated NPs showed highest ζ size and lowest ζ potential than other NPs. The migration and tumorsphere formation ability of CD44(+) was stronger than CD44(−). The effects of METase/5-Fu co-encaspulated NPs on inhibition cell growth was stronger than that of 5-Fu encaspulated NPs, while HA coated NPs showed significant target ability than that NPs without HA. METase supplementation promoted the inhibition effect of 5-Fu on thymidylate synthetase (TS), as well as cell apoptosis. Thein vivoexperiments demonstrated that HA coated NPs significantly inhibited tumor growth. It was concluded that HA-coated NPs enhance the target ability, while METase/5-Fu co-encaspulated NPs promote the inhibition effects on tumor growth in gastric cancer.

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Abstract 1065: A New Method for Stem Cell Imaging Using Contrast Ultrasound

Circulation ◽

10.1161/circ.118.suppl_18.s_642-a ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Wenjin Cui ◽

Xucai Chen ◽

Jianjun Wang ◽

Andrew Fisher ◽

Kang Kim ◽

...

Keyword(s):

Cell Imaging ◽

Pulse Sequence ◽

Mechanical Index ◽

Frequency Spectra ◽

Non Invasive ◽

Density Centrifugation ◽

Transmission Electron ◽

Therapy Strategies ◽

Contrast Ultrasound

Background : Mesenchymal stem cells (MSCs) are a promising new cardiac reparative therapy. The distribution of delivered MSCs is poorly understood due to limited methods to track them in vivo . To test the hypothesis that ultrasound can detect MSCs, gas-filled microbubbles (MBs) were developed for MSC uptake. Methods : Perfluorocarbon gas-filled MBs were synthesized from a biodegradable polymer. Cultured rat and human bone-marrow derived MSCs were dwelled with MBs (12 hrs), washed, and suspended in medium. MSC uptake of MBs and MB retention of gas were confirmed with transmission electron microscopy (TEM) and density centrifugation. Spectral analysis of free MB response to up to 10MHz ultrasound was performed. 2nd harmonic and contrast pulse sequence (CPS) 2D echo imaging (7MHz) of MB-labeled and unlabeled MSCs was performed at a mechanical index (MI) 0.3 and 1.9. Videointensity was measured in 200 frames/capture. Results: Frequency spectra of free MBs contained 2nd and 3rd harmonics, indicating MB non-linearity. TEM showed MBs within MSCs (Figure ). By density centrifugation, MSCs with MBs were less dense than MSCs alone, confirming intracellular MB gas retention. Videointensity (gray scale units) of MSCs containing MBs vs MSCs alone was higher at both low MI (35±2 vs 0±0 harmonic, p<0.005; 21±2 vs 15±0 CPS, p<0.005), and high MI (14±2 vs 6±1 harmonic, p<0.005; 6±2 vs 0±0 CPS, p<0.005). Conclusions : Our acoustically active polymer MBs are internalized by MSCs and render them detectable with ultrasound. Because the polymer degrades slowly, this approach may permit serial non-invasive in vivo ultrasound imaging of MSC fate, thus facilitating optimization of cell therapy strategies.

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Precise engineering of silver loaded polyvinyl alcohol nanogels for wound nursing care systems in operation room

Materials Express ◽

10.1166/mex.2021.1872 ◽

2021 ◽

Vol 11 (1) ◽

pp. 85-92

Author(s):

Lin Cai

Keyword(s):

Polyvinyl Alcohol ◽

Potential Candidate ◽

Drug Release Profile ◽

Transmission Electron ◽

Care Systems ◽

Rapid Healing ◽

Healing Of Skin Wounds ◽

Mediated Reduction ◽

Silver Nitrate Solutions

This study was designed to establish the composition of wound bandages based on silver nanoparticle (AgNP)loaded polyvinyl alcohol (PVA) nanogels. The AgNP nanogel (Ag-nGel) was fabricated by the fructose-mediated reduction of silver nitrate solutions within the PVA matrix. The influence of different experimental limitations on PVA nanogel formations were examined. The nanogel particle sizes were evaluated by transmission electron microscopy and determined to range from ∼10–50 nm. Additionally, glycerol were added to the Ag-nGels, and the resulting compositions (Ag-nGel-Glu) were coated on cotton fabrics to generate the wound bandaging composite. The cumulative drug release profile of the silver from the bandage was found to be ∼38% of the total loading after two days. Additionally, antibacterial efficacy was developed for gram positive and negative microorganisms. Moreover, we examined in vivo healing of skin wounds formed in mouse models over 21 days. In contrast to the untreated wounds, rapid healing was perceived in the Ag-nGel-Glu-treated wound with less damaging. These findings indicate that Ag-nGel-Glu-based bandaging materials could be a potential candidate for wound bandaging applications in the future.

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Abstract 531: Tie-2/Cre--Mediated Conditional Deletion of Lipid Phosphate Phosphatase-3 Reveals Its Role in Endothelial Cell Apoptosis

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.32.suppl_1.a531 ◽

2012 ◽

Vol 32 (suppl_1) ◽

Author(s):

Ishita Chatterjee ◽

Kishore K Wary

Keyword(s):

Endothelial Cells ◽

Endothelial Cell ◽

Genome Wide Association Study ◽

Vascular Endothelial Cell ◽

Protein Levels ◽

Conditional Deletion ◽

Transmission Electron ◽

Increased Risk

Rationale: A recent genome-wide association study (GWAS) has linked a frequently occurring variation in the LPP3 (also known as PPAP2b) loci to increased risk of coronary heart disease (CAD). However, the in vivo function of LPP3 in vascular endothelial cell is incompletely understood. Goal: To address the endothelial cell (EC) specific function of Lpp3 in mice. Results: Tie-2/Cre mediated Lpp3 deletion did not affect normal vasculogenesis in early embryonic development, in contrast, in late embryonic stages it led to impaired angiogenesis associated with hemorrhage, edema and late embryonic lethal phenotype. Immunohistochemical staining followed by microscopic analyses of mutant embryos revealed reduced fibronectin and VE-cadherin expression throughout different vascular bed, and increased apoptosis in CD31+ vascular structures. Transmission electron microscopy (TEM) showed the presence of apoptotic endothelial cells and disruption of adherens junctions in mutant embryos. LPP3-knockdown in vitro showed an increase in p53 and p21 protein levels, with concomitant decrease in cell proliferation. LPP3-knockdown also decreased transendothelial electrical resistance (TER), interestingly re-expression of ß-catenin cDNA into LPP3-depleted endothelial cells partially restored the effect of loss of LPP3. Conclusion: These results suggest the ability of LPP3 to regulate survival and apoptotic activities of endothelial cells during patho/physiological angiogenesis.

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Analytical High-resolution Electron Microscopy Reveals Organ-specific Nanoceria Bioprocessing

Toxicologic Pathology ◽

10.1177/0192623317737254 ◽

2017 ◽

Vol 46 (1) ◽

pp. 47-61 ◽

Cited By ~ 6

Author(s):

Uschi M. Graham ◽

Robert A. Yokel ◽

Alan K. Dozier ◽

Lawrence Drummy ◽

Krishnamurthy Mahalingam ◽

...

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

High Resolution ◽

Analytical Electron Microscopy ◽

High Resolution Electron Microscopy ◽

Dark Field ◽

Transmission Electron ◽

Analytical Electron ◽

Organ Specific

This is the first utilization of advanced analytical electron microscopy methods, including high-resolution transmission electron microscopy, high-angle annular dark field scanning transmission electron microscopy, electron energy loss spectroscopy, and energy-dispersive X-ray spectroscopy mapping to characterize the organ-specific bioprocessing of a relatively inert nanomaterial (nanoceria). Liver and spleen samples from rats given a single intravenous infusion of nanoceria were obtained after prolonged (90 days) in vivo exposure. These advanced analytical electron microscopy methods were applied to elucidate the organ-specific cellular and subcellular fate of nanoceria after its uptake. Nanoceria is bioprocessed differently in the spleen than in the liver.

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Human Islet Amyloid Polypeptide Fibril Binding to Catalase: A Transmission Electron Microscopy and Microplate Study

The Scientific World JOURNAL ◽

10.1100/tsw.2010.73 ◽

2010 ◽

Vol 10 ◽

pp. 879-893 ◽

Cited By ~ 10

Author(s):

Nathaniel G. N. Milton ◽

J. Robin Harris

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Islet Amyloid Polypeptide ◽

Amyloid Β ◽

Human Islet ◽

Islet Amyloid ◽

Human Islet Amyloid Polypeptide ◽

Transmission Electron

The diabetes-associated human islet amyloid polypeptide (IAPP) is a 37-amino-acid peptide that forms fibrilsin vitroandin vivo. Human IAPP fibrils are toxic in a similar manner to Alzheimer's amyloid-β (Aβ) and prion protein (PrP) fibrils. Previous studies have shown that catalase binds to Aβ fibrils and appears to recognize a region containing the Gly-Ala-Ile-Ile sequence that is similar to the Gly-Ala-Ile-Leu sequence found in human IAPP residues 24-27. This study presents a transmission electron microscopy (TEM)—based analysis of fibril formation and the binding of human erythrocyte catalase to IAPP fibrils. The results show that human IAPP 1-37, 8-37, and 20-29 peptides form fibrils with diverse and polymorphic structures. All three forms of IAPP bound catalase, and complexes of IAPP 1-37 or 8-37 with catalase were identified by immunoassay. The binding of biotinylated IAPP to catalase was high affinity with a KDof 0.77nM, and could be inhibited by either human or rat IAPP 1-37 and 8-37 forms. Fibrils formed by the PrP 118-135 peptide with a Gly-Ala-Val-Val sequence also bound catalase. These results suggest that catalase recognizes a Gly-Ala-Ile-Leu—like sequence in amyloid fibril-forming peptides. For IAPP 1-37 and 8-37, the catalase binding was primarily directed towards fibrillar rather than ribbon-like structures, suggesting differences in the accessibility of the human IAPP 24-27 Gly-Ala-Ile-Leu region. This suggests that catalase may be able to discriminate between different structural forms of IAPP fibrils. The ability of catalase to bind IAPP, Aβ, and PrP fibrils demonstrates the presence of similar accessible structural motifs that may be targets for antiamyloid therapeutic development.

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