Anti-obesity and anti-diabetic effects of ethanol extract of Artemisia princeps in C57BL/6 mice fed a high-fat diet

Artemisia princeps is commonly used as a food ingredient and in traditional Asian medicine. In this study, we examined the effects of long-term administration of an ethanol extract of A. princeps (APE) on body weight, white adipose tissue, blood glucose, insulin, plasma and hepatic lipids, and adipocytokines in C57BL/6 mice fed a high-fat diet. Daily feeding of a 1% APE diet for 14 weeks normalized elevated body weight, white adipose tissue, and plasma glucose and insulin levels, and delayed impaired glucose tolerance in mice a fed high-fat diet. These events were not observed in mice fed a control diet containing 1% APE. Liver triglyceride and cholesterol levels were similar in mice fed a 1% APE-diet and those fed a control diet. In the high-fat diet groups, APE inhibited hepatic fatty acid synthase (FAS) and suppressed the elevation of plasma leptin, but had no effect on adiponectin levels. These findings suggest that the regulation of leptin secretion by APE may inhibit FAS activity with subsequent suppression of triglyceride accumulation in the liver and adipose tissues. Inhibition of lipid accumulation can, in turn, lead to improvements in impaired glucose tolerance.     

Reaction mechanism of fluoroacetate dehalogenase from Moraxella sp. B

Fluoroacetate dehalogenase (EC 3.8.1.3) catalyzes the dehalogenation of fluoroacetate and other haloacetates. The amino acid sequence of fluoroacetate dehalogenase from Moraxella sp. B is similar to that of haloalkane dehalogenase (EC 3.8.1.5) from Xanthobacter autotrophicus GJ10 in the regions around Asp-105 and His-272, which correspond to the active site nucleophile Asp-124 and the base catalyst His-289 of the haloalkane dehalogenase, respectively (Krooshof, G. H., Kwant, E. M., Damborsky, J., Koca, J., and Janssen, D. B. (1997) Biochemistry 36, 9571-9580). After multiple turnovers of the fluoroacetate dehalogenase reaction in H218O, the enzyme was digested with trypsin, and the molecular masses of the peptide fragments formed were measured by ion-spray mass spectrometry. Two 18O atoms were shown to be incorporated into the octapeptide, Phe-99-Arg-106. Tandem mass spectrometric analysis of this peptide revealed that Asp-105 was labeled with two 18O atoms. These results indicate that Asp-105 acts as a nucleophile to attack the alpha-carbon of the substrate, leading to the formation of an ester intermediate, which is subsequently hydrolyzed by the nucleophilic attack of a water molecule on the carbonyl carbon atom. A His-272 --> Asn mutant (H272N) showed no activity with either fluoroacetate or chloroacetate. However, ion-spray mass spectrometry revealed that the H272N mutant enzyme was covalently alkylated with the substrate. The reaction of the H272N mutant enzyme with [14C]chloroacetate also showed the incorporation of radioactivity into the enzyme. These results suggest that His-272 probably acts as a base catalyst for the hydrolysis of the covalent ester intermediate.     

Involvement of R-cadherin in the early stage of glomerulogenesis

The earliest commitment to the formation of glomeruli is recognizable in S-shaped bodies. Although cell-cell adhesion seems likely to play a crucial role in this process, how glomerular epithelial cells segregate from the other parts of the nephron is unknown. In this study, immunofluorescence microscopy and monoclonal antibodies specific for mouse R-, E-, P- and N-cadherins were used to examine which of these adhesion molecules are involved in glomerulogenesis of the mouse kidney. Weak R-cadherin staining was first found in the vesicle stage, becoming restricted to glomerular visceral epithelial cells (VEC) during the S-shaped body stage. The intensity of this staining became stronger in the capillary loop stage, whereas parietal epithelial cells (PEC) and tubular cells did not stain. In the maturing stage, VEC gradually lost their staining for R-cadherin. E-cadherin was detected in ureteric buds and the upper limb of S-shaped bodies. From the capillary loop to the maturing stage, anti-E-cadherin stained epithelial cells in all tubule segments, but no label was seen in VEC or PEC. P-cadherin was also stained in the ureteric buds and in the upper limb of S-shaped bodies. N-Cadherin was weakly stained in cells at the vesicle stage, but thereafter staining of N-cadherin was not detected at any stage of glomerular formation. Immunoelectron microscopy of differentiating VEC was performed using antibodies specific to alpha-catenin, which is associated with cadherin. Subsequently, immunogold particles identifying alpha-catenin were localized on junctions between primary processes of VEC. These findings indicate that R-cadherin is uniquely expressed in differentiating VEC, suggesting an important role in the early stages of glomerulogenesis.     

Distribution of vitronectin in plasma and liver tissue: relationship to chronic liver disease

To clarify the clinical significance of vitronectin, we compared the concentration of plasma vitronectin with serum fibrous markers and liver function test values in patients with chronic liver diseases. We also evaluated the vitronectin content in the liver by means of enzyme-linked immunosorbent assay and the localization of vitronectin in liver tissue with enzyme immunohistochemistry. In chronic liver disease, the concentration of plasma vitronectin was significantly lower than that in healthy controls, being related to the severity of liver disease. The plasma levels of vitronectin showed no correlation to fibrous markers but a significant correlation with those of serum albumin and prothrombin time. On the other hand, the content of vitronectin in liver tissue was significantly increased in chronic liver disease compared with that in normal controls. In the normal liver, vitronectin was observed in the portal area by light microscopy. In chronic hepatitis and cirrhosis, vitronectin was found in the connective tissue around the portal and central veins and in the areas of piecemeal and focal necrosis. These findings suggested that vitronectin is deposited in injured tissue through the process of repair and fibrosis and plays an important role as an adhesive protein. Moreover, the lower levels of plasma vitronectin in chronic liver disease may be due to its decreased synthesis, deposition or both in injured tissue.     

Degradation of polyetherurethane by subcutaneous implantation into rats. I. Molecular weight change and surface morphology

The pharmacological characteristics of the 3-oxamethano-prostaglandin I1 compound (+)-methyl [2-[(2R,3aS,4R,5R,6aS)-octahydro-5-hydroxy-4- [(E)-(3S,5S)-3-hydroxy-5-methyl-1-nonenyl]-2-pentalenyl]etho xy] acetate (SM-10902, CAS 139403-31-9), a novel stable analogue of prostacyclin and its free acid, SM-10906, were studied. SM-10902 was rapidly deesterified to its free acid in rabbit and human serum. SM-10902 and SM-10906 exhibited antiplatelet potency against ADP-induced aggregation in rabbit and human platelets. In the presence of diisopropyl fluorophosphate, an esterase inhibitor, the antiplatelet activity of SM-10902 was markedly reduced, to much less than that of SM-10906. SM-10906 inhibited platelet aggregation induced by various inducers in several species and enhanced the cyclic AMP (cAMP) level in human platelets. These activities were nearly equal to those of prostaglandin (PG) E1 and less than those of PGI2. SM-10906 relaxed isolated rabbit mesenteric and bovine coronary arteries, and elevated the cAMP level in bovine coronary arteries. SM-10906 given intravenously exhibited a sustained reduction in blood pressure based on vasodilation in ganglion-blocked, angiotensin II-supported rats. SM-10902 applied to the guinea-pig auricles increased the skin temperature, but SM-10906 and PGI2 showed no such effect. In conclusion, SM-10902, which is considered to be a prodrug of SM-10906, was suggested to exert its anti-platelet and vasodilator activities through the increase of cAMP. Since SM-10902 penetrates well into the skin, it may be useful as an external preparation to improve peripheral circulatory insufficiency.     

G-CSF increases secretion of urokinase-type plasminogen activator by human lung cancer cells

AIMS: To examine the feasibility of using the human iris in vivo for the assessment of the interaction between tyramine and monoamine oxidase (MAO) inhibitors. To examine the relative roles of the two forms of MAO in terminating the response to sympathomimetic amines in the iris, by comparing the effects of single oral doses of moclobemide, a selective MAO-A inhibitor, and selegiline, a selective MAO-B inhibitor, on mydriatic responses to tyramine. METHODS: Twelve healthy male volunteers participated in three monthly sessions, each associated with ingestion of one capsule (moclobemide 450 mg, selegiline 10 mg, or placebo), according to a double-blind, balanced, cross-over design. Tyramine hydrochloride eye-drops (75 mM, 2 x 10 microl) were instilled three times in the left conjuctival sac at 40 min intervals. Pupil diameter was monitored with a binocular infrared television pupillometer before and for 4.5 h after ingestion of the capsule. The pupillary response to tyramine was expressed as the area under the pupil diameter x time curve (arbitrary units). A blood sample was taken before and 2 h after ingestion of the capsule, for the assay of platelet MAO-B activity, and plasma 3,4-dihydroxyphenylglycol (DHPG) concentration, an index of MAO-A activity. Platelet MAO activity was assayed radiochemically, using [14C]-phenylethylamine as substrate, and plasma DHPG by high performance liquid chromatography (h.p.l.c.). The results were analysed using analysis of variance with repeated measures, followed by Bonferroni's corrected t-test, using a significance criterion of P < 0.05. RESULTS: Both moclobemide and selegiline, compared with placebo, caused significant miosis in the right (untreated) eye. The changes in pupil diameter (mm +/- s.e. mean) from the pretreatment measurement were: placebo -0.09 +/- 0.07, moclobemide -0.52 +/- 0.09, selegiline -0.26 +/- 0.1. The mydriatic response to tyramine was potentiated by moclobemide, compared with the response recorded in the presence of placebo. The responses to tyramine (arbitrary units +/- s.e. mean) were: placebo 77.08 +/- 11.65, moclobemide 140.25 +/- 18.9, selegiline 72.75 +/- 12.35. Both moclobemide and selegiline significantly reduced platelet MAO activity, compared with placebo. The changes in platelet MAO activity (nmol h(-1) mg(-1) protein +/- s.e. mean) from the pretreatment level were: placebo 0.5 +/- 0.62, moclobemide -6.7 +/- 0.66, selegiline -17.7 +/- 0.87. Moclobemide significantly reduced plasma DHPG concentration, compared with placebo. The changes in plasma DHPG concentration (nmol l(-1) +/- s.e. mean) from the pretreatment level were: placebo -0.01 +/- 0.24, moclobemide -4.98 +/- 0.32, selegiline -0.51 +/- 0.26. CONCLUSIONS: The potentiation of tyramine-evoked mydriasis by moclobemide is likely to reflect the inhibition of MAO-A activity in the iris, consistent with the activity of this enzyme in sympathetic nerve terminals. The lack of effect of selegiline on tyramine-evoked mydriasis argues against a role of MAO-B in terminating the effects of sympathomimetic amines in the iris. The effects of the two drugs on platelet MAO activity and plasma DHPG concentration are in agreement with previous reports and consistent with the relative selectivity of moclobemide for MAO-A and of selegiline for MAO-B. The miosis caused by the two MAO inhibitors is likely to be due to a central sympatholytic action of the drugs.     

Post-prandial serum hyaluronan concentration in patients with chronic liver disease

Serum hyaluronan measurement is an option for diagnosing cirrhosis and assessing liver fibrosis, but it is of little use in the diagnosis of chronic hepatitis and compensated liver cirrhosis. It is generally known that intake of food results in elevation of the serum hyaluronan concentration. This work was designed to determine whether a change in the serum hyaluronan concentration after eating might reflect the hepatic sinusoidal endothelial cell impairment in chronic liver diseases. The chronological measurement of serum hyaluronan concentration after eating was performed after an overnight fast in 31 patients with chronic hepatitis, 31 cirrhotic patients, and 8 healthy subjects. The hyaluronan concentration in the loading test increased with the severity of the liver disease in the patients with chronic hepatitis, being significantly higher in the patients with moderate or a higher grade of necroinflammation than in those with a minimal grade, and also significantly higher in patients with stage 3 fibrosis than in those with stage 2 or less. The elevation of the concentration after eating in patients with liver cirrhosis was marked and the range did not overlap with that in patients with chronic hepatitis. Even in 14 patients with compensated liver cirrhosis whose hyaluronan concentration pre-prandially was less than 200 ng/ml, the range of the post-prandial peak concentration did not overlap with that in the chronic hepatitis patients. These results suggest that the evaluation of post-prandial serum hyaluronan concentration is potentially useful for assessing the grading of necroinflammation and staging of fibrosis in patients with chronic hepatitis, as well as for diagnosing compensated liver cirrhosis.     

Operation control of internally conductor cooled cable system

The development of 275 kV internally-conductor-cooled cable systems is under way for application to long-distance large-capacity (1500 MVA/cct) underground transmission systems. From the viewpoint of the reliability and the energy economy of these systems, the operational control system for the cooling facilities is especially important, because the facilities require large cooling capacity due to the large heat loss of the cable conductor. The cooling device characteristics are described, and the effects of operation control on energy savings are examined. A long-term field test has shown that the computer-controlled operation system is very useful. Simulation results for the operational control system confirm that calculated values are in good agreement with measurement results     

Photodimerization of Coumarin‐Derived Pentacyclo[9.5.1.13,9.15,15.17,13]octasiloxane to Fabricate a Three‐Dimensional Organic–Inorganic Hybrid Material

An organic–inorganic hybrid material was prepared from a pentacyclo[9.5.1.1^3,9.1^5,15.1^7,13]octasiloxane bearing eight coumarin groups. The coumarin groups were photodimerized by UV‐light irradiation to connect the monomer units of the octasiloxane. Using a concentrated solution, the intermolecular photodimerization of these coumarin groups leaded to the cross‐linking of the octasiloxane, fabricating an organic–inorganic hybrid material with a three‐dimensional nanostructure. Whereas in dilute solution the intramolecular photodimerization was preferred to the intermolecular reaction, resulting in no formation of polymeric material.