Suppressive effect of short-interfering RNA on hyperglycemia-induced expression of intercellular adhesion molecule-1 on cultured vascular endothelial cells

PURPOSE: The pathology of diabetic retinopathy involves endothelial dysfunction, in which leukocyte adhesion to the vascular endothelium via intercellular adhesion molecule-1 (ICAM-1) may play a key role. Short-interfering RNAs (siRNAs) are unique modulators of gene expression in mammalian cells. The purpose of this study was to evaluate the enhanced effect of hyperglycemia and the attenuating effect of siRNAs on ICAM-1 expression in cultured endothelial cells. METHODS: Human umbilical vein endothelial cells (HUVECs) were seeded onto 24-well culture plates. The following day, ICAM-1-specific siRNAs were transfected using Lipofectamine 2000. Glucose (15, 30, or 45 mM) or interleukin-1ss as a positive control was added to the medium to stimulate ICAM-1. After 48 hours, the HUVECs were collected to measure the ICAM-1 expression by enzyme-linked immunosolvent assay. Fluoresceinated siRNAs were transfected into HUVECs to confirm transfection of the siRNAs into HUVECs by fluorescein microscopy. RESULTS: Glucose enhanced the ICAM-1 expression in a dose-dependent manner. ICAM-1 expression stimulated by hyperglycemia decreased significantly in the HUVECs transfected with corresponding siRNAs. Transfection of siRNAs was confirmed with enhanced fluorescence in HUVECs incubated with control siRNAs. CONCLUSIONS: These results suggested that hyperglycemia stimulated protein expression of ICAM-1 and that siRNAs suppressed gene expression of ICAM-1 in HUVECs. The RNA-targeting approach using siRNAs may provide a novel therapeutic option for diabetic retinopathy.     

Effect of grapefruit pulp on the pharmacokinetics of the dihydropyridine calcium antagonists nifedipine and nisoldipine

The effect of the intake of 200 g of grapefruit pulp (corresponding to one grapefruit) on the pharmacokinetics of the calcium antagonists nifedipine (NF) and nisoldipine (NS) were investigated in 8 healthy Japanese male volunteers. A crossover design was used for the study: group I did not ingest any grapefruit (control group); group II ingested grapefruit 1 h after drug administration; and group III ingested grapefruit 1 h before drug administration. The intake of grapefruit pulp increased the plasma concentrations of both NF and NS, an effect that has previously been reported with grapefruit juice. The increase was most marked when grapefruit was eaten before drug administration. For both NF and NS, subjects who ingested grapefruit 1 h before drug administration exhibited a greater Cmax and AUC0-24 than did subjects in the control group. For NF, the Cmax was 1.4 times higher and the AUC0-24 1.3 times larger in group III than in group I. For NS, the Cmax was 1.5 times higher and the AUC0-24 1.3 times larger in group III than in group I. The increase in the AUC0-24 was significant for both drugs (p < 0.05). The finding that the ratios of Cmax and AUC0-24 for unchanged drug and metabolites did not vary greatly among the three groups for either drug suggests that the increase in serum concentration produced by grapefruit intake may be due to other factors than an inhibitory effect on drug metabolism. Also, the increases in Cmax and AUC0-24 of NS produced by grapefruit intake were smaller than those produced by grapefruit juice intake, indicating that grapefruit pulp and juice have different effects on the pharmacokinetics.     

Targeting Efficiency of Galactosylated Liposomes to Hepatocytes in Vivo: Effect of Lipid Composition

Purpose. To investigate the effects of the lipid composition of galactosylated liposomes on their targeted delivery to hepatocytes. Methods. Several types of liposomes with a particle size of about 90 nm were prepared using distearoyl-L-phosphatidylcholine (DSPC), cholesterol (Chol) and cholesten-5-yloxy-N-(4-((1-imino-2-D-thiogalactosylethyl)amino)butyl)formamide (Gal-C4-Chol), and labeled with [³H]cholesterol hexadecyl ether. Their tissue disposition was investigated in mice following intravenous injection. The binding and internalization characteristics were also studied in HepG2 cells. Results. Compared with [³H]DSPC/Chol (60:40) liposomes, [³H]D-SPC/Chol/Gal-C4-Chol (60:35:5) liposomes exhibit extensive hepatic uptake. Separation of the liver cells showed that galactosylated liposomes are preferentially taken up by hepatocytes, whereas those lacking Gal-C4-Chol distribute equally to hepatocytes and nonparenchymal cells (NPC). Increasing the molar ratio of DSPC to 90% resulted in enhanced NPC uptake of both liposomes, suggesting their uptake via a mechanism other than asialoglycoprotein receptors. DSPC/Chol/Gal-C4-Chol (60:35:5) and DSPC/Chol/Gal-C4-Chol (90:5:5) liposomes exhibited similar binding to the surface of HepG2 cells, but the former were taken up faster by the cells. Conclusions. The recognition of galactosylated liposomes by the asialoglycoprotein receptors is dependent on the lipid composition. Cholesterol-rich galactosylated liposomes, exhibiting less non-specific interaction and greater receptor-mediated uptake, are better for targeting drugs to hepatocytes in vivo.     

Estimating an EQ-5D population value set: the case of Japan

Quality adjustment weights for quality-adjusted life years (QALYs) are available with the EQ-5D Instrument, which are based on a survey that quantified the preferences of the British public. However, the extent to which this British value set is applicable to other, especially non-European, countries is yet unclear. The objectives of this study are (a) to compare the valuations obtained in Japan and Britain, and (b) to explore a local Japanese value set. A diminished study design is employed, where 17 hypothetical EQ-5D health states are evaluated as opposed to 42 in the British study. The official Japanese version of the instrument and the Time Trade-Off method are used to interview 543 members of the public. The results are: firstly, the evaluations obtained in Japan and those from Britain differ by 0.24 on average on a [-1, +1] scale, and mean absolute error (MAE) in predicting the Japanese preferences with the British value set is 0.23. Secondly, comparable regressions suggest that the two peoples have systematically different preference structures (p<0.001 for 8 of 12 coefficients; F-test). Thirdly, using alternative models, the predictions are improved so that the local Japanese value set achieves MAE in the order of 0.01.     

Synthesis and microbiological activity of some novel N-[2-(p-substitutedphenyl)-5-benzoxazolyl]-cyclohexyl carboxamide, -cyclohexyl acetamide and -cyclohexyl propionamide derivatives

The synthesis and microbiological activity of a new series of N-[2-(p-substitutedphenyl)-5-benzoxazolyl]-cyclohexyl carboxamide, -cyclohexyl acetamide and -cyclohexyl propionamide derivatives (4-11) is described. The in vitro microbiological activity of the compounds was determined against gram-positive, gram-negative bacteria and the yeast Candida albicans in comparison with standard drugs. Microbiological results indicated that the synthesized compounds possessed a broad spectrum of activity against the tested microorganisms.     

Involvement of the raphé pallidus in the suppressive effect of preoptic warming on non-shivering thermogenesis in rats

Thermogenesis in the brown adipose tissue (BAT) is activated by the stimulation of the ventromedial hypothalamic nucleus (VMH). Local warming of the preoptic area (PO) suppresses this response. Injection of the GABA(A) receptor antagonist bicuculline into the caudal periaqueductal gray (cPAG), where excitatory neurons for BAT thermogenesis are located, did not influence the suppressive effect of PO warming. On the other hand, after bicuculline injection into the raphé pallidus, where excitatory neurons for BAT thermogenesis are also located, VMH stimulation produced BAT thermogenesis even during PO warming. The present results suggest that the inhibitory signal from the PO reaches the raphé pallidus and not the cPAG for the control of BAT thermogenesis.     

Energy metabolism and turnover are increased in mice lacking the cholecystokinin-B receptor

Cholecystokinin (CCK) is an important gastrointestinal hormone as well as a neurotransmitter. Two types of CCK receptors, types A and B, have been identified. The CCK-A receptor is involved in satiety, food intake and behavior, whereas the B receptor is involved in anxiety. We recently produced CCK-A, -B and AB receptor knockout mice to study the role of these receptors in energy metabolism. Daily energy intake and expenditure were significantly greater in CCK-BR(-/-) and CCK-AR(-/-)BR(-/-) mice than CCK-AR(-/-) and wild-type [CCK-AR(+/+)BR(+/+)] mice. Relative liver and kidney weights (g/kg body) were significantly greater in CCK-AR(-/-)BR(-/-) mice than in wild-type mice. Energy metabolism and energy turnover were increased in mice with a disruption of the CCK-BR gene, although the underlying mechanism is unknown.     

Falling asleep while driving and automobile accidents among patients with obstructive sleep apnea-hypopnea syndrome

Among 448 patients with obstructive sleep apnea-hypopnea syndrome (OSAHS), 40 patients (8.9%) had been involved in one or more automobile accidents during the preceding 5 years. The main cause of these accidents was falling asleep while driving. Excessive sleepiness during driving was associated with an Epworth sleepiness scale (ESS) score of > 11 and/or an apnea-hypopnea index (AHI) of > 15. The automobile accident rate among 182 patients with severe OSAHS (AHI > 30) was significantly higher than the rate among 106 simple snorers (AHI < 5). Although four of the simple snorers were involved in automobile accidents, their ESS scores were all very high (15 or more).     

Prognostic factors in elderly patients with acute myelogenous leukemia: a single center study in Japan

We retrospectively analyzed data of 47 patients aged 60 years or older, hospitalized in our institution with the diagnosis of acute myelogenous leukemia (AML), and searched for prognostic factors. Induction with anthracyclines significantly correlated with better complete remission (CR) rate (P = 0.0016) and overall survival (OS) (P < 0.001). Another factor significantly affecting CR rate was higher age (> 70 years) (P = 0.042). Therapy-non-related factors predictive for shorter OS in univariate analyses were age older than 70 years (P = 0.003), percentage of blasts in bone marrow more than 80% (P = 0.048), serum lactate dehydrogenase level higher than 250 U l(-1) (P = 0.032). In stepwise cox proportional hazard regression model, all the four factors predictive for poor OS remained to be independently and significantly prognostic for shorter OS. Only two patients receiving anthracyclines died within 30 days and the frequency was not different from that in patients not receiving anthracyclines. The use of anthracyclines as induction therapy is recommended even in the elderly patients.     

Angiogenesis in the human corpus luteum

Angiogenesis is important for the formation and development of the corpus luteum and for maintenance of luteal function. Blood vessel regression is an important physiological phenomenon in the corpus luteum, which is associated with tissue involution during structural luteolysis. Angiogenesis actively occurs during the early luteal phase and is completed by the mid-luteal phase. Perivascular cells (pericytes) increase in number from the early luteal phase to the mid-luteal phase, suggesting that blood vessels are gradually stabilized until the mid-luteal phase. In the corpus luteum undergoing luteolysis, blood vessels and pericytes decrease in number, which is related to structural involution. In the corpus luteum of early pregnancy, the number of blood vessels with pericytes increases, suggesting that angiogenesis occurs again, accompanied by blood vessel stabilization. These changes in vasculature of the corpus luteum are regulated by the collaboration with vascular endothelial growth factor, which is involved in proliferation of vascular endothelial cells, and angiopoietins, which are involved in stabilization of blood vessels. This review focuses on angiogenesis, blood vessel stabilization and blood vessel regression during the divergent phases of luteal formation, luteal regression and luteal rescue by pregnancy. (Reprod Med Biol 2008; 7 : 91–103)