Nagasaki International University

About: Nagasaki International University is a education organization based out in Nagasaki, Japan. It is known for research contribution in the topics: Monolayer & Eastern blot. The organization has 264 authors who have published 617 publications receiving 12698 citations. The organization is also known as: Nagasaki kokusai daigaku.

Physical Activity and Blood Lipids and Lipoproteins in Dialysis Patients

Abstract: The relationship between physical activity and blood lipids and lipoproteins in dialysis patients is reviewed in the context of the potentially confounding factors such as nutritional intake, cigarette smoking, obesity, alcohol intake, and physical activity levels in the general population and additional confounding factors such as mode of dialysis and diabetes in dialysis patients. The known associations in the general population of physical activity with high-density-lipoprotein cholesterol subfractions and apolipoprotein A-I are more pronounced in hemodialysis patients than in peritoneal dialysis patients even after adjusting for these confounding factors. Examining studies on the effects of physical activity on blood lipids and lipoproteins, the most consistent observation is the noted decrease in triglycerides and increase in high-density-lipoprotein cholesterol and insulin sensitivity in hemodialysis patients. The changes in lipids and lipoproteins in hemodialysis patients could be caused by changes in activity levels of lipoprotein lipase, insulin sensitivity, and/or glucose metabolism. Future research investigating the relationship between physical activity and blood lipids and lipoproteins in dialysis patients should direct research towards the underlying mechanisms for changes in blood lipids and lipoproteins.

Fluidizing and Solidifying Effects of Perfluorooctylated Fatty Alcohols on Pulmonary Surfactant Monolayers.

Abstract: Pulmonary surfactant (PS) preparations based mainly on bovine or porcine extracts are commonly administered to patients with neonatal respiratory distress syndrome (NRDS) for therapy. The preparations are sufficiently effective to treat NRDS; however, they are associated with a risk of infection and involve costly purification procedures to achieve batch-to-batch reproducibility. Therefore, we investigated the mechanism and interfacial behavior of synthetic PS preparations containing a mimicking peptide (KLLKLLLKLWLKLLKLLL, Hel 13-5). In particular, a hybrid PS formulation with fluorinated amphiphiles is reported from the perspective of surface chemistry. Fluorinated amphiphiles are characterized by exceptional chemical and biological inertness, high oxygen-dissolving capacity, low surface tension, excellent spreading ability, and high fluidity. These properties are superior to those for the corresponding hydrocarbon analogs. Indeed, a small amount of fluorinated long-chain alcohols enhances the effectiveness of the model PS preparation for in vitro pulmonary functions. Moreover, the mode of the improved efficacy differs depending on the hydrophobic chain length in the alcohols. For alcohols with a short fluorocarbon (FC) chain, the monolayer phase of the model PS preparation remains disordered (fluidization). However, the addition of alcohols containing a long FC chain reduces the disordered/ordered phase transition pressure and the growth of ordered domains of the monolayer (condensation). Furthermore, repeated compression-expansion isotherms of the monolayers, which can simulate respiration in the lung, suggest irreversible elimination of the short-FC alcohol into the subphase and enhancement of the squeeze-out phenomenon of certain PS components by solid-like monolayer formation induced by the long-FC alcohol. We demonstrated that fluorinated amphiphiles may be used as additives for synthetic or commercial PS preparations for RDS treatment.

Argonaute2 Protein in Rat Spermatogenic Cells Is Localized to Nuage Structures and LAMP2-Positive Vesicles Surrounding Chromatoid Bodies.

Abstract: Localization of Argonaute2 (AGO2) protein--an essential component for the processing of small interfering RNA (siRNA)-directed RNA interference (RNAi) in RNA-induced silencing complex (RISC) in nuage of rat spermatogenic cells--was evaluated by immunofluorescence microscopy (IFM) and immunoelectron microscopy (IEM). AGO2 was shown, for the first time, to be localized to four previously classified types of nuage: irregularly shaped perinuclear granules (ISPGs), intermitochondrial cement (IMC), satellite bodies (SBs), and chromatoid bodies (CBs). Dual IEM staining for AGO2/Maelstrom (MAEL) protein or AGO2/MIWI protein demonstrated that AGO2 is colocalized with MAEL or MIWI proteins in these types of nuage. Dual IFM and IEM staining of AGO2/lysosomal-associated membrane protein 2 (LAMP2) showed that CB in round spermatids are in contact with and surrounded by LAMP2-positive vesicles, whereas nuage in pachytene spermatocytes are not. Taken together, our findings indicate that: (i) AGO2 in pachytene spermatocytes functions in ISPGs, IMC, and SBs; (ii) AGO2 in round spermatids functions in CBs, and that CBs are associated with lysosomal compartments.

Expression of a Testis-Specific Nuclear Protein, TRA98, in Mouse Testis during Spermatogenesis. A Quantitative and Qualitative Immunoelectron Microscopy (IEM) Analysis

Abstract: TRA98 is a testis-specific nuclear protein, but its biological role is unclear. We analyzed the localization of TRA98 in developing spermatogenic cells using immunofluorescence (IF) and immunoelectron microscopy (IEM). TRA98 was localized exclusively to the nuclei. In spermatocytes, IF staining was associated with certain sub-nuclear structures to show a reticular pattern; the XY body was strongly stained. In spermatids, both reticular and punctate staining patterns were observed. In late spermatids, staining decreased as cell dif-ferentiation proceeded. However, epididymal sperm were strongly stained when smear preparations were not fixed, or followed by treatment with 4 M urea or 2% mercaptoethanol. IEM showed that gold signals were closely associated with electron-dense masses but not with the nucleoli. We then investigated the expression of TRA98 in differentiating spermatocytes using a quantitative IEM technique. A small expression peak was observed around stage II-III and a second large peak was noted at stage XI. In spermatids, a single expres-sion peak was observed at step 5; labeling density then decreased gradually but did not reach zero. In early spermatids, heterochromatin was stained much more than euchromatin. The results suggest that the function of TRA98 increases at three points during spermatogenesis. In addition, TRA98 is maintained in the sperm head and carried into the egg after fertilization.

Occurrence of 5'-deoxyadenosylcobalamin and its physiological function as the coenzyme of methylmalonyl-CoA mutase in a marine eukaryotic microorganism, Schizochytrium limacinum SR21.

Abstract: A marine eukaryotic microorganism, Schizochytrium limacinum SR21, had the ability to absorb and accumulate exogenous cobalamin, which was converted to the cobalamin coenzymes 5'-deoxyadenosylcobalamin (20.1%) and methylcobalamin (29.6%). A considerably high activity (about 38 mU/mg protein) of 5'-deoxyadenosylcobalamin-dependent methylmalonyl-CoA mutase (EC 5.4.99.2) involved in amino acid and odd-chain fatty acid metabolism was found in the cell homogenate of S. limacinum SR21. The enzyme was purified to homogeneity and characterized.