Endogenously synthesized liver triglyceride (TG) is secreted into the blood in the form of TG-rich very low density lipoprotein (VLDL) containing lipids and lipoproteins such as phospholipids, cholesterol ester, and apolipoprotein B (apoB). It is known that microsomal TG transfer protein (MTP) in the liver catalyzes the assembly of TG, the conversion of apoB into VLDL, and the secretion of VLDL into the blood.1-3) Recently, it was reported that calcium antagonists inhibit the secretion of VLDL from rat hepatocytes into the blood. [4][5][6] From these results, [4][5][6] it could be speculated that MTP activity might be stimulated by the increase of intracellular Ca 2ϩ . A few studies have reported that the calcium ionophore (A23187) and thapsigargin, an inhibitor of Ca 2ϩ -ATPase in the endoplasmic reticulum (ER), inhibit VLDL secretion by hepatocytes. 7,8) At present, despite many studies on MTP activity, the role of Ca 2ϩ on MTP activity in hepatocytes is poorly understood, and the inhibition of MTP activity is associated with the suppression of hypertriglyceridemia and atherosclerosis. In recent, in another experiment, we found that MTP activity was relatively higher under high Ca 2ϩ level (10.1Ϯ1.8 mM/protein-mg) than under low Ca 2ϩ level (6.2Ϯ1.9 mM/protein-mg) in liver tissues, and its activity was about 2-fold higher than under low Ca 2ϩ level, and had a relative association with hyperlipoproteinemia. It is inferred that MTP activity may have a correlation with Ca 2ϩ level in the liver. Accordingly, we investigated the effects of Ca 2ϩ on MTP activity in hepatocytes, our data demonstrate that MTP activity may be activated by Ca 2ϩ and calmodulin, and may inhibit hypertriglyceridemia by decreasing the level of Ca 2ϩ in hepatocytes. MATERIALS AND METHODS MaterialsHanks' balanced salts (HBSS) buffer (without calcium chloride, magnesium sulfate, and sodium bicarbonate) for collagenase perfusion and Williams' medium E (with L-glutamine but without sodium bicarbonate) for hepatocytes culture were purchased from Sigma (St. Louis, MO, U.S.A.). MTP assay kits were obtained from Calbiochem ® (an affiliate of Merck KGaA, Darmstadt, Germany). Lipid assay kits were obtained from Nissui Pharmaceutical (Tokyo, Japan). Collagenase (type IV) and other chemical reagents were obtained from Sigma (St. Louis, MO, U.S.A.).Preparation of Hepatocytes and Cell Culture Freshly isolated hepatocytes were prepared from adult male Sprague-Dawley rats weighing between 200 and 250 g. The hepatocytes were isolated by the collagenase-liver perfusion method of Berry and Friend. 9) Hepatocytes viability was assessed by trypan blue exclusion. Cell viability assessed by trypan blue exclusion averaged 95%. Hepatocytes with 95% viability were washed three times with washing buffer [Williams' medium E, 23.8 M NaHCO 3 , 0.5 mM dexamethasone, and 15 mM HEPES, pH 7.4 supplemented with 1000 U/l penicillin, 1 mg/l streptomycin, 1 mM insulin]. Hepatocytes (10 6 cells/well) suspended in culture medium (washing buffer supplemented with 10% fetal bovine ...

Ruthenium-alkylidene initiated ring-opening metathesis polymerization has been realized under solid-state conditions by employing a mechanochemical ball milling method. This method promotes greenness and broadens the scope to include mechano-exclusive products....

Chemical upcycling of poly(bisphenol A carbonate) (PC) was achieved in this study with hydroxamic acid nucleophiles, giving rise to synthetically valuable 1,4,2-dioxazol-5-ones and bisphenol A. Using 1,5,7-triazabicyclo[4.4.0]-dec-5-ene (TBD), non-green carbodiimidazole or phosgene carbonylation agents used in conventional dioxazolone synthesis were successfully replaced with PC, and environmentally harmful bisphenol A was simultaneously recovered. Assorted hydroxamic acids exhibited good-to-excellent efficiencies and green chemical features, promising broad synthetic application scope. In addition, a green aryl amide synthesis process was developed, involving one-pot depolymerization from polycarbonate to dioxazolone followed by rhodium-catalyzed CÀ H amidation, including gramscale examples with used compact discs.

Ruthenium alkylidene mediated ring‐opening metathesis polymerizations (Ru‐ROMP) are evaluated in green chemical solvents to increase their green metrics. The Ru‐ROMP of representative monomers of norbornene, oxa‐norbornene, and cyclooctadiene were compared in reference solvents (tetrahydrofuran and chloroform) and green solvents (2‐methyl tetrahydrofuran, ethyl acetate, dimethyl carbonate, and acetone). The results showed that the use of a green solvent is promising. All green solvents exhibited excellent Ru‐ROMP efficiency while their chain length controls were sensitive to solvents and monomers. Among the candidates, dimethyl carbonate expressed the general applicability of various combinations of monomers and solvents.

Ruthenium-alkylidene initiated ring-opening metathesis polymerization (Ru-ROMP) was realized under solid-state conditions employing a mechanochemical ball milling method, promoting greenness and broadening scope. High-speed ball milling provided sufficient mixing and energy to the reaction mixture comprised of the catalyst and solid monomers, thus eliminating the need for solvents. Studies on the catalytic species and ball milling parameters (liquid-assisted grinding, vibration frequency, and ball size) revealed that mechanical energy regulated solid-state Ru-ROMP and it follows similar mechanistic features of solution-phase reactions. The solubility and miscibility of monomer and Ru-initiator are not a limitation in solid-state ball milling. Without the use of a solvent, a wide spectrum of solid monomers, including ionomer, fluorous monomer, and macromonomers, were successfully polymerized. Finally, effective direct copolymerization of immiscible monomers such ionic/hydrophobic and ionic/fluorous monomers resulted in a set of copolymers that are difficult to make using traditional solution procedures.