• Journal of Microbiology and Biotechnology
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• v.31 no.5
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• pp.645-658
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• 2021

Porins are essential for the viability of Gram-negative bacteria. They ensure the uptake of nutrients, can be involved in the maintenance of outer membrane integrity and define the antibiotic or drug resistance of organisms. The function and structure of porins in proteobacteria is well described, while their function in photoautotrophic cyanobacteria has not been systematically explored. We compared the domain architecture of nine putative porins in the filamentous cyanobacterium Anabaena sp. PCC 7120 and analyzed the seven candidates with predicted OprB-domain. Single recombinant mutants of the seven genes were created and their growth capacity under different conditions was analyzed. Most of the putative porins seem to be involved in the transport of salt and copper, as respective mutants were resistant to elevated concentrations of these substances. In turn, only the mutant of alr2231 was less sensitive to elevated zinc concentrations, while mutants of alr0834, alr4741 and all4499 were resistant to high manganese concentrations. Notably the mutant of alr4550 shows a high sensitivity against harmful compounds, which is indicative for a function related to the maintenance of outer membrane integrity. Moreover, the mutant of all5191 exhibited a phenotype which suggests either a higher nitrate demand or an inefficient nitrogen fixation. The dependency of porin membrane insertion on Omp85 proteins was tested exemplarily for Alr4550, and an enhanced aggregation of Alr4550 was observed in two omp85 mutants. The comparative analysis of porin mutants suggests that the proteins in parts perform distinct functions related to envelope integrity and solute uptake.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.371-372
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• 2002

It is well known that red blood cells (RBCs) are suffered from chronic stresses in systemic circulation. The objective of this study is to clarify the effect of the aging of RBCs on rheological properties and hemolysis. Initially, RBCs age fractionation was performed by using a high-speed centrifugation (15[min] at 1500[G]), then young and aged RBCs were suspended in plasma to adjust the hematocrit level of 40[%]. After this pretreatment, the viscosity was measured by using a capillary type and a cone-plate type viscometers, respectively, and the hemolysis test was carried out by a seesaw type shaker. Results from these experiments showed that the viscosity of the aged RBCs measured by the capillary viscometer was increased by 10[%] as compared with that of the young RBCs. Under the condition of all shear zones, the viscosity of the aged RBCs was increased in case of using the cone-plate type viscometer. And the hemolytic level was increased twice as the aging. The data obtained in this study indicated that the ability of aggregation of RBCs was increased and the deformability of RBCs membrane got lower with the aging. Furthermore, it was exhibited that the fragility of RBCs ’ membrane was increased with the aging.

• Korean Journal Plant Pathology
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• v.10 no.2
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• pp.83-91
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• 1994

Stem tissues of tomato plants (cv. Kwanyang) inoculated with Phytophthora capsici were examined by light and electron microscopy to compare early cytological differences between comaptible and incompatible interactions of tomatoes with the fungus. Twenty four hours after inoculation, the compatible isolate S 197 colonized severely the epidermis, cortex, and xylem vessels of stem tissue, whereas only few fungal cells colonized the stem tissues inoculated with the incompatible isolate CBS 178.26. Fragmented plasma membrane, distorted chloroplast, degraded cell wall, remnants of host cytoplasm were early ultrastructural features of the damaged host cell observed both in the compatible and incompatible interaction, a number of vesicles were distributed in the space between fungal cell walls and plasma membrane. The degradation of host cell walls by P. capsici was more pronounced in the compatible than the incompatible interactions. The incompatible interactions of tomato cells with P. capsici were characterized by formation of host cell wall apposition in the cortical parenchyma cells, indicating that the apposition of electron-dense material from the host cell walls may function as a plant defense reaction to the fungus. The fungal cells encased by wall appositions had abnormal cytoplasm and separated plasma membranes. The haustorium which formed from the fungal hyphae did not further penetrate through the host wall apposition and cytoplasmic aggregation, especially in the incompatible reactions. In contrast, the haustorium of the compatible isolate S 197 was not encased by wall appositions.

• Nutrition Research and Practice
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• v.6 no.2
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• pp.106-112
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• 2012

This study was conducted to investigate the effects of $Sasa$ $quelpaertensis$ bamboo and green tea on plasma and liver lipids, platelet aggregation, and erythrocyte membrane Na channels in ovariectomized (OVX) rats. Thirty female rats were OVX, and ten female rats were sham-operated at the age of 6 weeks. The rats were divided into four groups at the age of 10 weeks and fed the experiment diets: sham-control, OVX-control, OVX-bamboo leaves (10%), or OVX-green tea leaves (10%) for four weeks. Final body weight increased significantly in the OVX groups compared with that in the sham-control, whereas body weight in the OVX-green tea group decreased significantly compared with that in the OVX-control ($P$ < 0.01). High density lipoprotein (HDL)-cholesterol level decreased in all OVX groups compared with that in the sham-control rats ($P$ < 0.05) but without a difference in plasma total cholesterol. Plasma triglycerides in the OVX-green tea group were significantly lower than those in the sham-control or OVX-control group ($P$ < 0.05). Liver triglycerides increased significantly in the OVX-control compared with those in the sham-control ($P$ < 0.01) but decreased significantly in the OVX-green tea group compared with those in the OVX-control or OVX-bamboo group ($P$ < 0.01). Platelet aggregation in both maximum and initial slope tended to be lower in all OVX rats compared with that in the sham-control rats but was not significantly different. Na-K ATPase tended to increase and Na-K cotransport tended to decrease following ovariectomy. Na-K ATPase decreased significantly in the OVX-green tea group compared with that in the OVX-control group ($P$ < 0.01), and Na-K cotransport increased significantly in the OVX-bamboo and OVX-green tea groups compared with that in the OVX-control ($P$ < 0.05). Femoral bone mineral density tended to be lower in OVX rats than that in the sham-control, whereas the green tea and bamboo leaves groups recovered bone density to some extent. The results show that ovariectomy caused an increase in body weight and liver triglycerides, and that green tea was effective for lowering body weight and triglycerides in OVX rats. Ovariectomy induced an increase in Na efflux via Na-K ATPase and a decrease in Na efflux via Na-K cotransport. Furthermore, consumption of green tea and bamboo leaves affected Na efflux channels, controlling electrolyte and body water balance.

• Textile Coloration and Finishing
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• v.10 no.5
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• pp.56-62
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• 1998

In the prior study, the dyeing behaviors of Milling Cyanine 5R on silk fiber in aqueous dyeing liquor including small amount of organic compounds were investigated. The most effective compound was acetophenone which increased dye uptake as well as dyeing rate. In this study, the role of the acetophenone in dyeing of silk with Milling Cyanine 5R was studied. By addition of acetophenone into the dye solution, the molar absorptivity of Milling Cyanine 5R increased, and the wavelength of maximum absorption was shifted to longer wavelength, namely bathochromic shifted. This shows that the acetophenone prevents the dye to aggregate, and increases the number of monomeric dye molecule relative to the dye solution without acetophenone. This fact was also confirmed by the increase of the permeation rate of the dye through cellulose semipermeable membrane from the dye solution including the acetophenone. From these results, the acetophenone acts as a prohibitor of dye aggregation, increases the number of monomeric dye molecules even at relatively low temperature, and makes the dyes penetrate into the fiber easier.

• BMB Reports
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• v.29 no.1
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• pp.68-72
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• 1996

Ursodeoxycholic acid (UDCA) and lithocholic acid (LCA), secondary bile acids, have been shown to have a cell differentiation activity in mouse F9 teratocarcinoma stem cells. Treatment with bile acids induced morphological changes, including cytoplasmic and nuclear membrane blebbing, aggregation of organelles, and chromatin condensation, corresponding to apoptosis. Moreover, the bile acids induced intemucleosomal DNA fragmentation, a hallmark of apoptosis. In addition, the expression of c-jun was increased, but that of c-myc and laminin was decreased during apoptosis induced by the bile acids in F9 cells. These results suggest that the bile acids can induce apoptosis in F9 cells. Furthermore, the c-jun expression may be related to the apoptosis induced by UDCA or LCA in F9 cells.

• The Plant Pathology Journal
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• v.31 no.4
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• pp.323-333
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• 2015

As sessile organisms, plants are exposed to persistently changing stresses and have to be able to interpret and respond to them. The stresses, drought, salinity, chemicals, cold and hot temperatures, and various pathogen attacks have interconnected effects on plants, resulting in the disruption of protein homeostasis. Maintenance of proteins in their functional native conformations and preventing aggregation of non-native proteins are important for cell survival under stress. Heat shock proteins (HSPs) functioning as molecular chaperones are the key components responsible for protein folding, assembly, translocation, and degradation under stress conditions and in many normal cellular processes. Plants respond to pathogen invasion using two different innate immune responses mediated by pattern recognition receptors (PRRs) or resistance (R) proteins. HSPs play an indispensable role as molecular chaperones in the quality control of plasma membrane-resident PRRs and intracellular R proteins against potential invaders. Here, we specifically discuss the functional involvement of cytosolic and endoplasmic reticulum (ER) HSPs/chaperones in plant immunity to obtain an integrated understanding of the immune responses in plant cells.

• Journal of Ginseng Research
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• v.18 no.1
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• pp.44-48
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• 1994

In adrenaline-stimulated human platelets, panaxadiol (PD) and panaxatriol (PT) from Panax ginseng C.A. Meyer did not inhibit the $Ca^{2+}$-innux, but inhibited the formation of thromboxane $A_2$ and the platelet aggregations. It seems that PD and PT block a pathyway interconvefing arachidonic acids (20:4) to thromboxane $A_2$ (TX $A_2$), because the amount of $Ca^{2+}$ which phospholipase C or phospholipase $A_2$ requires to liberate 20 : 4 from membrane phospholipids was increased by PD and PT. These results mean that PH and PT have an antiplatelet effect by Inhibiting the formation of TX $A_2$.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.6 no.2
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• pp.116-130
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• 2020

The aging society is globally one of biggest issue because it is related with various degenerative brain disease such as dementia, Parkinson's disease, Alzheimer's disease, multiple sclerosis, and cerebrovascular disease. These diseases are characterized by misfolded-protein aggregation; another pathological trait is "neuroinflammation". In physiological state, the resting microglia cells are activated and it removes abnormal synapses and cell membrane debris to maintain the homeostasis. In pathological state, however, microglia undergo morphological change form 'resting' to 'activated amoeboid phenotype' and the microglia cells are accumulated by neuronal damage, the inflammatory reactions induced nerve metamorphosis with a variety of neurotoxic factors including cytokines, chemokines, and reactive oxygen species. Thus, the activated microglia cell with various receptors (TSPO, COX, CR, P2XR, etc.) was perceived as important biomarkers for imaging the inflammatory progression. In this review, we would like to introduce the current status of the development of radiotracers that can image activated microglia.

• Parasites, Hosts and Diseases
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• v.23 no.2
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• pp.269-284
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• 1985

The metabolism of Entamoeba histolytica would be affected by various environmental factors, and alteration of the environment was known to afEect the fine structure of 5. histolytica. The present study was designed electronmicroscopically to investigate the ultrastructure and enzyme activities in the aEonic and conventional strains of 5. histolytica. The trophozoites of axenically cultivated HK-9 strain and conventional YS-27 and YS-49 strains of 5. histolytica were collected and liKed with 4% paraformaldehyde/0.1M cacodylate buffier(pH 74), After washing them by centrifugation, 1% warm agar was added in the sediment. Solidified agar with the trophozoites was cut into $lmm^3$ cubes, and incubated in the various substrates to observe enzyme activities. Then, the specimen was post-fixed with 3% glutaraldehyde/0.1M cacodylate buffer (PH 7.4) and 1% osmium tetroBide/0.1M cacodylate buffier (pH 7.4) , dehydrated in ascending ethanol series and embedded in epoxy resin. These were sectioned on an ultramicrotome and observed with a transmission electronmicroscope. The procedures for the observation of the fine structure were same as the above, except for the incubation in the substrate. The sections were stained with uranyl acetate and lead citrate. For the observation of the surface of the amoebae, scanning-electronmicroscopy was carried out. The results obtained in the present study are summarized as follows: 1. The fuzzy coat around double-layered plasma membrane of 5. histolytica was more irregularly and densely distributed in the conventional strains (YS-27, YS-49 strains) than in the axonic strain (HK-9 strain). 2. The endosomes, button bodies and chromatin material were surrounded by a double-layered nuclear membrane having scattered nuclear fores. The paranuclear body, mono- or double-layered vacuoles, vacuolar membrane whorls, rosette-like cylindrical bodies, aggregation of cylindrical bodies and helical bodies were found in the cytoplasm of the amoebae. Helical bodies and glycogen granules were generally abundant, while a few smooth endoplasmic reticula were observed in the cytoplasm. 3. Alkaline phosphatase activity was mainly demonstrated in the plasma membrane, limiting membranes of vacuoles and smooth endoplasmic reticula. ATPase activity was observed in the nucleus, limiting membranes of vacuoles and vacuolar membrane whorls. 4. Acid phosphatase activity was commonly demonstrated in the limiting membranes an contents of vacuoles, Iysosome-like organelles, plasma membrane and the button bodies in the nucleus. The activity was more weakly demonstrated in the HK-9 strain than in the other conventional strains of 5. histolytica. No peroBidase activity was observed in the amoeba strains employed in the present study. 5. With a scanning electron-microscope, no distinct structural differences were observed between the amoeba strains. All the trophozoite forms of the amoebae showed crater-like depressions and rugged features on the outer surface.