• Mass Spectrometry Letters
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• v.11 no.2
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• pp.25-29
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• 2020

Pseudopodia are dynamic actin cytoskeleton-based membrane protrusions of cells that enable directional cell migration. Pseudopodia of cancer cells play key roles in cancer metastasis. Recent studies using pseudopodial subcellular fractionation methodologies combined with mass spectrometry-based proteomic profiling have provided insight into the pseudopodiome that control the protrusions of invasive metastatic cancer cells. This review highlights how to characterize the protein composition of pseudopodia and develop strategies to identify biomarkers or drug candidates that target reduction or prevention of metastatic cancer.

• Journal of Species Research
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• v.9 no.4
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• pp.448-454
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• 2020

Nine free-living heterotrophic flagellates were cultured from marine intertidal sediments and freshwater sediments from Korea. These species are described with uninterpreted records based on light microscopy of living cells and reported taxonomically for the first time from Korea. Diagnostics of these species are as follows; Notosolenus hemicircularis: 9-11.8 ㎛ long with flagellar reservoir, ventrally flattened and dorsally convex with hyaline semicircular collar around short anterior neck, and 8 ridges on cell surface. Thecamonas tranhens: 4.5-7.1 ㎛ long, plastic with proboscis comprising an anterior flagellum surrounded by membranous sleeve. Bodomorpha minima: 4.5-7.0 ㎛ long, rigid with small rostrum in anterior end and active anterior flagellum. Cercomonas hiberna: 5.6-10.9 ㎛ long, very plastic with pseudopodia, cytoplasmic strand and 1 or 2 contractile vacuoles. Cercomonas pellucida: 7.5-13 ㎛ long, plastic with pseudopodia, cytoplasmic strand and single contractile vacuole. With nucleus closely connected to basal bodies. Eocercomonas echina: 4.7-6.5 ㎛ long, plastic with pseudopodia, cytoplasmic strand and 1 or 2 contractile vacuoles. Paracercomonas astra: 5.7-7.3 ㎛ long, moderately metabolic with pseudopodia, cytoplasmic strand and 1 or 2 contractile vacuoles. Paracercomonas minima: 5-9 ㎛ long, metabolic with pseudopodia, cytoplasmic strand and single contractile vacuole. Paracercomonas producta: 6.1-9.9 ㎛ long, very metabolic with pseudopodia, long cytoplasmic strand and single contractile vacuole.

• Parasites, Hosts and Diseases
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• v.42 no.1
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• pp.35-40
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• 2004

The nfa 1 gene was cloned from a cDNA library of pathogenic Naegleria fowleri by immunoscreening; it consisted of 360 bp and produced a 13.1 kDa recombinant protein (rNfa1) that showed the pseudopodia-specific localization by immunocytochemistry in the previous study. Based on the idea that the pseudopodia-specific Nfa1 protein mentioned above seems to be involved in the pathogenicity of N. fowleri, we observed the effect of an anti-Nfa1 antibody on the proliferation of N. fowleri trophozoites and the cytotoxicity of N. fowleri trophozoites on the target cells. The proliferation of N. fowleri trophozoites was inhibited after being treated with an anti-Nfa1 polycional antibody in a dose-dependent manner for 48 hrs. By a light microscope, CHO cells co-cultured with N. fowleri trophozoites (group I) for 48 hrs showed severe morphological destruction. On the contrary, CHO cells co-cultured with N. fowleri trophozoites and anti-Nfa1 polyclonal antibody (1:100 dilution) (group II) showed less destruction. In the LDH release assay results, group I showed 50.6% cytotoxicity, and group II showed 39.3%. Consequently, addition of an anti-Nfa1 polyclonal antibody produced a decreasing effect of in vitro cytotoxicity of N. fowleri in a dose-dependent manner.

• Journal of fish pathology
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• v.17 no.3
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• pp.179-189
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• 2004

Morphological structure and sporogenesis of myxosporean parasite, Parvicapsula anisocaudata from cultured olive flounder, Paralichthys olivaceus were examined by light and transmission electron microscopies. Numerous round early stages, spindle-shaped disporic or monosporic pseudoplasmodia, asymmetrical thin-walled mature spores were found inthe lumen of renal tubule and urinary bladder. Long pseudopodia or short projections from cytoplasm of pseudoplasmodia make the parasite attach firmly to host tissues. Spore development was mono- or disporous with no pansporoblast formation. Sporoplasmic cell was partially surrounded by two capsulogenic cells, and capsulogenic cells were enveloped by two flattened valvogenic cells. Capsulogenesis and valvogenesis followed general patterns seen in that of other myxosporean.

• Journal of Species Research
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• v.5 no.3
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• pp.381-384
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• 2016

Two marine amoebae Vannella bursella (Page, 1974) Smirnov et al., 2007 and Pseudoparamoeba sp. were encountered from marine coastal waters of Masan Bay and Garorim Bay (Korea), respectively. These species are described with uninterpreted records based on light-microscopy of living cells and reported taxonomically for the first time from Korea. Diagnostics of these species are as follows. Vannella bursella: size in vivo, $17-29{\mu}m$ long with flattened ovoid, semicircular locomotive forms. Pseudoparamoeba sp.: size in vivo, $10-15{\mu}m$ long with elongated locomotive forms, producing a few short conical pseudopodia from anterior hyaline zone.

• Applied Microscopy
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• v.28 no.4
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• pp.513-525
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• 1998

The spermatogenetic process in the edible giant snail is similar to those in the other snails, except for the axoneme formation process. In this study, the axoneme formation process in the giant snail was mainly examined by means of electron microscopy. The tail portion of a spermatozoon is about $160{\mu}m$ long, and extends straight to the rear, surrounded by two large and long mitochondria in spiral forms. A number of glycogen particles $(40\sim70nm)$ are found in the swollen matrix of the mitochodria. The axoneme which composes the tail of a spermatozoon is surrounded by $7\sim10$ lamella-form fibrous sheaths of about $0.2{\mu}m$ in thickness. Most of the mature spermatozoa are found to be clustered into a group of $5\sim7$ ea in syncytial bridges formed by cytoplasmic processes. Sertoli cells contain glycogen particles, endoplasmic reticulum, a lot of mitochondria, and lipids in their cytoplasm. They protrude their filiform pseudopodia and phagocytize abnormal spermatids or spermaozoa.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.10
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• pp.6007-6012
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• 2013

ANXA2, a member of the annexin family, is overexpressed and plays important roles in tumor development. However, the significance of ANXA2 expression in gastric carcinoma has not been clarified.To elucidate its roles in growth of gastric cancer, ANXA2 expression in SGC-7901 cells was inhibited with a designated siRNA, then cell proliferation, cell cycling, apoptosis and motility were determined by MTT assay, flow cytometry, Hoechst 33342 staining and wound healing assay, respectively. To further assess the behavior of ANXA2 deleted SGC-7901 cells, changes of microstructures were observed under fluorescence microscopy, laser scanning confocal microscopy and electron microscopy. We found that inhibition of ANXA2 expression caused cell proliferation to decrease significantly with G1 arrest, motility to be reduced with changes in pseudopodia/filopodia structure and F-actin and ${\beta}$-tubulin expression, and apoptosis to be enhanced albeit without significance. At the same time, ANXA2 deletion resulted in fewer pseudopodia/filopodia, non-stained areas were increased, contact inhibition among cells reappeared, and expression of F-actin and ${\beta}$-tubulin was decreased, with induction of polymerized disassembled forms. Taken together, these data suggest that ANXA2 overexpression is important to maintain the malignancy of cancer cells, and this member of the annexin family has potential to be considered as a target for the gene therapy of gastric carcinoma.

• Applied Microscopy
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• v.31 no.3
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• pp.235-244
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• 2001

The aim of this study was to observe morphological changes of Trichomonas vaginalis after contact with human vaginal epithelial cells, by scanning electron microscope. The vaginal epithelial cells (VEC) (menstrual, days $5\sim10$) from normal women were mixed with T. vaginalis (VEC/trichomonads ratio of 1 : 10), and incubated for 30 min. The parasitic body was changed to a more elongated shape with pseudopodia or was flattened to ameboid transformation showing highly adherence to VEC.

• Journal of fish pathology
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• v.18 no.2
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• pp.119-124
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• 2005

Two species of myxosporean parasites - Parvicapsula anisocaudata and an unidentified myxosporean were found in the lumina of renal tubules and the tubular epithelium, respectively, from cultured olive flounder, Paralichthys olivaceus in Korea. The latter was also seen in interstitial tissue of spleen and interrenal gland of the head kidney. Group of pseudoplasmodia of P. anisocaudata were firmly attached on the epithelium of renal tubules through pseudopodia. In the renal tubule epithelium, a group of unidentified myxosporean trophozoites, which were 2-3 times larger than intraluminal trophozoites of P. anisocaudata, was observed. The parasites being burst out into the lumen was occasionally encountered with partial break of the epithelium. Although infection of P. anisocaudata and unidentified myxosporean parasites did not induce any cellular reaction of the host, occlusion of renal tubules and rupture of renal epithelium would impact negatively on the renal functions of severely infected fish.

• Applied Microscopy
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• v.15 no.1
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• pp.1-12
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• 1985

In this study, the pathway and date of migrating Primordial germ cells (PGCs) were observed light microscopically and ultrastructural changes of them during migration were observed by electron microscopic examination. For these purpose, alkaline phosphatase reactions were used for identifying the PGCs and acid phosphatase reactions were used for observing their degenerating activities. Also, effects of actinomycin D on the migration of PGCs were examined. According to these results, at the 9th gestation day, PGCs were observed in the endodermal cells of yolk sac, at the 11th gestation day, they were seen in the hindgut and then entered into the dorsal mesentery by the 13th gestation day. At the 14th gestation day, they were located in the genital ridges. When PGCs were located in the hindgut and genital ridges, the positive reactions of alkaline phosphatase were dominated, but acid phosphatase reactions were limited in all stage except they were in dorsal mesentery. However, these reactions were lessened in case of actinomycin D treatment. By electron microscopic examination, PGCs had pseudopodia, tail process, trailing cytoplasm and nuage as the ultrastructural characteristics. In addition, these morphological features were damaged by actinomycin D treatment.