Manipulating and imaging the shape of an electronic wave function by magnetotunneling spectroscopy

We measure the current due to electrons tunneling through the ground state of hydrogenic Si donors placed in a GaAs quantum well in the presence of a magnetic field tilted at an angle to the plane of the well. The component of B parallel to the direction of current compresses the donor wave function. By measuring the current as a function of the perpendicular component of B, we probe how the magnetocompression affects the spatial form of the wave function and observe directly the transition from Coulombic to magnetic confinement at high fields.

PAMELA results on the cosmic-ray antiproton flux from 60 MeV to 180 GeV in kinetic energy

The satellite-borne experiment PAMELA has been used to make a new measurement of the cosmic-ray antiproton flux and the antiproton-to-proton flux ratio which extends previously published measurements down to 60 MeV and up to 180 GeV in kinetic energy. During 850 days of data acquisition approximately 1500 antiprotons were observed. The measurements are consistent with purely secondary production of antiprotons in the Galaxy. More precise secondary production models are required for a complete interpretation of the results.

Increased intestinal absorption of mizoribine, an immunosuppressive agent, in cholestatic rats

The intestinal absorption of mizoribine, an imidazole nucleoside, is mediated by concentrative nucleoside transporter (CNT)1 and CNT2 in rat. Previously, bile and bile salts such as sodium glycocholate were found to suppress the intestinal absorption of mizoribine. In the present study, the contribution of bile on the intestinal absorption of mizoribine was further evaluated in rats. Cholestatic states were induced by an intraperitoneal injection (2 ml/kg) of 50% carbon tetrachloride (CCl4) dissolved in olive oil, or oral administration (100 mg/2 ml/kg) of alpha-naphthylisothiocyanate (ANIT) dissolved in olive oil. The animals were subjected to absorption studies 24 h after treatment. Cholestatic states were confirmed by measuring plasma concentrations of bile acids and bile flow rates. When oral bioavailability of mizoribine was estimated by the recovery amount in the urine, rats under cholestatic states exhibited significantly higher oral bioavailabilities than untreated control rats. In contrast, the intestinal absorption percentages of mizoribine from in-situ lavaged intestinal loops were the same magnitudes among untreated control, CCl4- and ANIT-treated rats. These results indicated that the increased oral bioavailability of mizoribine in cholestatic rats was not ascribed to the modulation of nucleoside transporter's expression. In conclusion, various diseased states accompanied with cholestasis may increase the oral bioavailability of mizoribine, possibly due to its less amounts of bile in the intestinal lumen.

Study on absorption sites of quinidine and methotrexate in rat intestine

Influx or efflux transporter(s), or both, are frequently involved in the intestinal absorption of various therapeutic drugs. In the present study, the effects of altered gastric emptying rates (GER) on intestinal absorption of quinidine (a substrate for P-glycoprotein, P-gp) and methotrexate (a substrate for multiple-transporters including proton-coupled folate transporter, PCFT) were examined to find their main absorption sites along the intestine employing rats. In untreated control rats, quinidine administered orally was rapidly absorbed from the proximal intestine, where P-gp is less expressed. Increased GER, which transferred an unabsorbable model compound to the middle intestine within 15 min after oral administration, exerted no significant effects on the extent of oral bioavailability of quinidine, whereas it increased the initial absorption rate greatly. Decreased GER, in which more than 50% of a model compound administered was retained in the stomach even 1 h after administration, decreased the onset time of intestinal absorption, but not the extent of oral bioavailability of quinidine. In untreated control rats, methotrexate was absorbed efficiently from the proximal intestine under acidic conditions, where PCFT is abundantly expressed. Increased GER significantly decreased, and decreased GER slightly increased the oral bioavailability of methotrexate. In conclusion, altered GER was found to affect the transporter-mediated intestinal absorption of drugs in different manners, depending on the solubility, membrane permeability, luminal concentration of the drug, luminal pH, substrate specificity, and the expression sites of transporter.

Intraperitoneal administration of telomerase-specific oncolytic adenovirus sensitizes ovarian cancer cells to cisplatin and affects survival in a xenograft model with peritoneal dissemination

Despite tremendous development in chemotherapy for ovarian cancer over the past few decades, the prognosis of advanced cases with massive peritoneal dissemination is still unsatisfactory, and novel treatment modalities that can combine with chemotherapy are urgently needed. We recently developed virotherapy for solid tumors using telomerase-specific replication-selective adenoviruses (Telomelysin: OBP-301), in which the human telomerase reverse transcriptase (hTERT) gene promoter has been inserted to direct tumor-specific E1 gene expression. In this study, we investigated the anti-tumor effects of OBP-301, combined with cisplatin (CDDP), on ovarian cancer cells. In vitro treatment of SKOV3 cells with OBP-301 at a multiplicity of infection (MOI) of 0.01–100 induced significant cell death in a dose-dependent manner, with moderate cytotoxicity at an MOI of 1–10 and maximal cytotoxicity at an MOI of 100. In contrast, OBP-301 treatment of normal human cells showed no significant cell death at an MOI of 1–10 and exhibited modest cytotoxicity at an MOI of 100. The effects of low-dose CDDP at 0.5–1 μM, which induced only 20% cell death, were significantly augmented by combination with OBP-301 at an MOI of 1–10, finally achieving 40% cell death. Such enhancement of CDDP sensitivity was also observed in CDDP-resistant ovarian cancer cells. The combinatorial effects were further tested using a xenograft mouse model of SKOV3 with peritoneal dissemination. After intraperitoneal administration of OBP-301, we confirmed that injected OBP-301 fused with the green fluorescent protein (GFP) gene (OBP-401) was preferentially localized to peritoneal disseminations, as determined by fluorescence imaging. Treatment of mice with CDDP at low dose (0.5 mg kg^–1) had modest effects, showing a 10% decrease in disseminations, whereas combination with intraperitoneal administration of OBP-301 at an MOI of 10 led to enhanced effects, achieving an approximately 80% decrease in disseminations. Kaplan–Meier analysis showed improved overall survival of mice treated with CDDP plus OBP-301 compared with CDDP alone. These findings support the therapeutic potential of intraperitoneal administration of OBP-301 to sensitize ovarian cancer cells to CDDP.

Interaction of Rhei Rhizoma extract with cytochrome P450 3A and efflux transporters in rats

Traditional Chinese herbal medicines are frequently prescribed in pharmacotherapy in Japan. In the present study, we evaluated the possible interaction of several herbal extracts including Rhei Rhizoma extract with cytochrome P450 (CYP) 3A and efflux transporters such as P-glycoprotein and multidrug resistance-associated protein (MRP) 2. Rhei Rhizoma extract (100 microg/ml) significantly suppressed the CYP3A-mediated 6beta-hydroxylation of testosterone in hepatic microsomes, and increased the extent of bioavailability of midazolam, a typical CYP3A substrate, in rats. Also, Rhei Rhizoma extract (300 microg/ml) significantly suppressed P-glycoprotein-mediated efflux transport of rhodamine 123 (Rho123) in rat everted intestine. In an in-vivo study, Rhei Rhizoma extract added to intestinal perfusate at a concentration of 300 microg/ml significantly suppressed the intestinal exsorption of Rho123, though it exerted no effect on the biliary excretion of Rho123. Furthermore, the in-vitro and in-vivo MRP2-mediated intestinal efflux of 2,4-dinitrophenyl-S-glutathione was significantly suppressed by Rhei Rhizoma extract (1000 microg/ml). In conclusion, Rhei Rhizoma extract, which is taken orally at doses of 0.5-1 g each or 1-3 g daily in clinical practice, may cause pharmacokinetic herb-drug interactions in the process of the intestinal and/or hepatic CYP3A-mediated drug metabolism and P-glycoprotein- and/or MRP2-mediated efflux transport in the intestine.

HBx protein is indispensable for development of viraemia in human hepatocyte chimeric mice

The non-structural X protein, HBx, of hepatitis B virus (HBV) is assumed to play an important role in HBV replication. Woodchuck hepatitis virus X protein is indispensable for virus replication, but the duck hepatitis B virus X protein is not. In this study, we investigated whether the HBx protein is indispensable for HBV replication in vivo using human hepatocyte chimeric mice. HBx-deficient (HBx-def) HBV was generated in HepG2 cells by transfection with an overlength HBV genome. Human hepatocyte chimeric mice were infected with HBx-def HBV with or without hepatic HBx expression by hydrodynamic injection of HBx expression plasmids. Serum virus levels and HBV sequences were determined with mice sera. The generated HBx-def HBV peaked in the sucrose density gradient at points equivalent to the generated HBV wild type and the virus in a patient's serum. HBx-def HBV-injected mice developed measurable viraemia only in continuously HBx-expressed liver. HBV DNA in the mouse serum increased up to 9 log(10) copies ml(-1) and the viraemia persisted for more than 2 months. Strikingly, all revertant viruses had nucleotide substitutions that enabled the virus to produce the HBx protein. It was concluded that the HBx protein is indispensable for HBV replication and could be a target for antiviral therapy.

Synthesis and pharmacological effects of new, N-substituted soft anticholinergics based on glycopyrrolate

To reduce the possibility of systemic side-effects in locally administered anticholinergics, two new N-substituted glycopyrrolate analogues designed using soft drug design approaches have been synthesized and evaluated in vitro and in vivo. Because stereospecificity is known to be important at muscarinic receptors, the new compounds SGM and SGE also have been prepared as their pure 2R isomers, 2R-SGM and 2R-SGE, by starting from optically pure (-)-cyclopentylmandelic acid, and the corresponding isomers were indeed found to be more active. The new soft glycopyrrolates were chemically more stable under acidic conditions, and the ethyl esters SGE were more stable than the methyl esters SGM. The new compounds were also found to be quite susceptible to extrahepatic metabolism, having half-lives of 20–30 min in rat plasma (in vitro), consistent with their soft nature. Binding studies at human muscarinic receptors (M1−M4) and guinea-pig ileum assays found 2R-SGM and 2R-SGE to have potencies somewhat less than, but close to, those of glycopyrrolate and N-methylscopolamine. They caused pupil dilation in rabbit eyes, but their mydriatic effects lasted for considerably less time than that of glycopyrrolate, and they did not induce dilation of the pupil in the contralateral, water-treated eyes, indicating that, in agreement with their soft nature, they are locally active, but safe and with a low potential to cause systemic side-effects.

Translocation of neonicotinoid insecticides from coated seeds to seedling guttation drops: a novel way of intoxication for bees

The death of honey bees, Apis mellifera L., and the consequent colony collapse disorder causes major losses in agriculture and plant pollination worldwide. The phenomenon showed increasing rates in the past years, although its causes are still awaiting a clear answer. Although neonicotinoid systemic insecticides used for seed coating of agricultural crops were suspected as possible reason, studies so far have not shown the existence of unquestionable sources capable of delivering directly intoxicating doses in the fields. Guttation is a natural plant phenomenon causing the excretion of xylem fluid at leaf margins. Here, we show that leaf guttation drops of all the corn plants germinated from neonicotinoid-coated seeds contained amounts of insecticide constantly higher than 10 mg/l, with maxima up to 100 mg/l for thiamethoxam and clothianidin, and up to 200 mg/l for imidacloprid. The concentration of neonicotinoids in guttation drops can be near those of active ingredients commonly applied in field sprays for pest control, or even higher. When bees consume guttation drops, collected from plants grown from neonicotinoid-coated seeds, they encounter death within few minutes.

G-to-A hypermutation in hepatitis B virus (HBV) and clinical course of patients with chronic HBV infection

BACKGROUND

The apolipoprotein B messenger RNA editing enzyme, catalytic polypeptide-like family of cytidine deaminases induce G-to-A hypermutation in hepatitis B virus (HBV) genomes and play a role in innate antiviral immunity. The clinical relevance of this protein family is unknown.

METHODS

We analyzed 33 instances in which 17 patients with chronic HBV infection experienced >2 increases of >100 IU/L in alanine aminotransferase (ALT) level; we used a quantitative differential DNA denaturation polymerase chain reaction assay to quantify the hypermutated HBV genomes observed during 21 of these 33 increases in ALT level.

RESULTS

Of the 9 increases in ALT level that involved a >5-fold increase (relative to basal levels) in the number of hypermutated genomes observed, 8 were associated with a >2-log reduction in plasma HBV DNA level. In contrast, a corresponding decrease in plasma HBV DNA level was observed for only 1 of the 12 increases in ALT level that did not involve an increase in the number of hypermutated genomes ( P<.001). Hepatitis B e antigen clearance was often observed in patients who experienced an increase in the number of hypermutated genomes. Interferon treatment induced hypermutation in HBV genomes in an animal model. However, there was no apparent increase in the number of hypermutated genomes among the majority of patients who received interferon therapy, probably because the number of hypermutated genomes had already increased prior to the initiation of therapy.

CONCLUSION

Our results suggest that a marked increase in the number of hypermutated genomes represents a strong immunological host response against the virus and is predictive of hepatitis B e antigen clearance and plasma HBV DNA level reduction.

Genetic Analysis of Susceptibility to Radiation-induced Apoptosis of Thymocytes in Mice

Genetic control of thymocyte susceptibility to radiation-induced apoptosis was investigated in BALB/cHeA, STS/A and five other strains of mice by counting pyknotic cells in a selected area of thymic cortex on histological specimens after whole-body X-irradiation. Number of dead cells increased almost linearly with doses (range 0.25-0.75 Gy) in BALB/cHeA and STS/A mice. However, dead cell counts in BALB/cHeA mice were more than twice those in STS/A mice at each dose. Of five other strains of mice, C57BL/6N and B10.BR mice exhibited a sensitive phenotype similar to BALB/cHeA mice, while C3H/HeAMsNrs and NFS/N mice showed a resistant phenotype similar to STS/A mice. A/J mice seemed to be rather resistant. A sex difference was not recognized in BALB/cHeA and STS/A mice. Resistance was dominant over susceptibility in the progenies of reciprocal crosses between the two strains, indicating an autosomal inheritance and no maternal effect. Segregation ratio of susceptible phenotype to resistant one in the backcrosses of female (BALB/cHeA x STS/A)F1 mice with male BALB/cHeA mice was not significantly different from 1:1 and all backcrosses of female (BALB/cHeA x STS/A)F1 mice with male STS/A mice exhibited a resistant phenotype. Results suggested that thymocyte susceptibility to radiation-induced apotosis is controlled by one major autosomal allele.

Detection of Human papillomavirus and cellular regulators p16INK4a, p53, and NF-kappaB in penile cancer cases in Kenya

Human papillomavirus (HPV) E6 and E7 gene products play a central role in the induction of benign proliferation and malignant transformation by interacting with several cellular regulatory proteins such as p53, p16(INK4a), and nuclear factor kappaB (NF-kappaB). In this study, HPV DNA was detected by in situ hybridization (ISH) and p53, p16(INK4a), and NF-kappaB by immunochemistry in 22 penile cancer cases in Kenya. HPV DNA was found in 68.2% of the cases. There was no difference in the p53- and p16(INK4a)-positivities in HPV DNA-positive and HPV DNA-negative cases. In HPV DNA-positive cases, the NF-kappaB positivity in the nucleus, cytoplasm, and nucleus and/or cytoplasm amounted to 73.3%, 93.3%, and 100%, respectively, while in HPV DNA-negative cases, a 28.7% NF-kappaB positivity of in the nucleus and/or cytoplasm was observed. It is concluded that NF-kappaB in penile cancer is expressed more frequently in the presence of HPV infection than in its absence.

Randomized trial of high-dose interferon-alpha-2b combined with ribavirin in patients with chronic hepatitis C: Correlation between amino acid substitutions in the core/NS5A region and virological response to interferon therapy

The aim of this study was to compare the efficacy of high-dose interferon (IFN)-alpha-2b with standard dose of IFN-alpha-2b in combination with ribavirin (RBV) for patients with chronic hepatitis C virus (HCV) infection, and to investigate the predictive factors associated with virological response. Two hundred Japanese patients with high HCV viral load (>100 KIU/ml) were randomized to 6 or 10 mega units (MU) of 24-week IFN-alpha-2b with RBV. Predictive factors were investigated; including pretreatment amino acid (aa) sequences of the core region and the IFN-sensitive determining region (ISDR). The sustained virological response rate was not different in the two groups (24% vs. 30%) but the incidence of depression was significantly higher in the 10 MU group than 6 MU group (7% vs. 0%, P = 0.02). Younger age (<60) and HCV genotype (2a/b) were significant predictors of sustained virological response. In patients infected with genotype 1b, substitutions of core aa 70 and/or 91 were predictive for non-virological response (P < 0.001), and substitutions in the ISDR was observed frequently in virological responders. Early viral kinetics study showed that serum HCV core antigen decreased more slowly in both patients with aa 70 and/or 91 substitutions in the core and with absence of substitutions in the ISDR. In conclusion, the use of a higher dose of IFN-alpha-2b in combination with RBV did not improve virological response but resulted in higher incidence of depression. Amino acid substitutions in the core and ISDR are predictive of virological response to the therapy in patients with genotype 1b and high viral load.

Statistical properties of directional ocean waves: the role of the modulational instability in the formation of extreme events

We discuss two independent, large scale experiments performed in two wave basins of different dimensions in which the statistics of the surface wave elevation are addressed. Both facilities are equipped with a wave maker capable of generating waves with prescribed frequency and directional properties. The experimental results show that the probability of the formation of large amplitude waves strongly depends on the directional properties of the waves. Sea states characterized by long-crested and steep waves are more likely to be populated by freak waves with respect to those characterized by a large directional spreading.

The leptomeningeal "ivy sign" on fluid-attenuated inversion recovery MR imaging in Moyamoya disease: a sign of decreased cerebral vascular reserve?

BACKGROUND AND PURPOSE

Moyamoya disease is an idiopathic occlusive cerebrovascular disorder with abnormal microvascular proliferation. We investigated the clinical utility of leptomeningeal high signal intensity (ivy sign) sometimes seen on fluid-attenuated inversion recovery images in Moyamoya disease.

MATERIALS AND METHODS

We examined the relationship between the degree of the ivy sign and the severity of the ischemic symptoms in 96 hemispheres of 48 patients with Moyamoya disease. We classified each cerebral hemisphere into 4 regions from anterior to posterior. In 192 regions of 24 patients, we examined the relationship between the degree of the ivy sign and findings of single-photon emission CT, including the resting cerebral blood flow (CBF) and cerebral vascular reserve (CVR).

RESULTS

The degree of the ivy sign showed a significant positive relationship with the severity of the ischemic symptoms (P < .001). Of the 4 regions, the ivy sign was most frequently and prominently seen in the anterior part of the middle cerebral artery region. The degree of the ivy sign showed a negative relationship with the resting CBF (P < .0034) and a more prominent negative relationship with the CVR (P < .001).

CONCLUSIONS

The leptomeningeal ivy sign indicates decreased CVR in Moyamoya disease.

Influence of angiotensin-converting enzyme gene polymorphism on development of athlete's heart

BACKGROUND AND HYPOTHESIS

Genetic influence on development of athlete's heart is uncertain. This study investigated whether angiotensin-converting enzyme (ACE) gene polymorphism influenced development of athlete's heart.

METHODS

Forty-three participants in a 100-km ultramarathon were classified on the basis of ACE gene polymorphism into a deletion group (n = 26) and an insertion group (n = 17). Echocardiograms were recorded to determine left ventricular end-diastolic and end-systolic diameters, interventricular septal thickness, left ventricular posterior wall thickness, left ventricular mass, and ejection fraction.

RESULTS

Left ventricular end-diastolic diameter (65.5 +/- 4.0 mm) and left ventricular mass (369.5 +/- 73.9 g) were significantly larger in the subjects with deletion than in those with insertion (57.4 +/- 4.2 mm, 306.5 +/- 93.7 g). However, no significant differences in the other parameters were noted.

CONCLUSIONS

In long-distance runners, ACE gene polymorphism of the D/D and D/I genotypes has a stronger influence on left ventricular hypertrophy than polymorphism of the I/I genotype.

Electroconvulsive therapy for burning mouth syndrome

OBJECTIVE

Burning mouth syndrome (BMS) is an orofacial pain disorder characterized by a chronic, idiopathic burning sensation of the oral mucosa that mostly affects middle-aged women. Although both psychological and neuropathological factors have been postulated to underlie BMS, the pathogenic mechanism of the condition remains controversial, as do the treatment strategies.

METHOD

A single case was reported.

RESULTS

Ms A, a 66-year-old woman with BMS type 1, which is characterized by daily burning pain associated with circadian variation, underwent electroconvulsive therapy (ECT). After the completion of 12 ECTs, the pain markedly diminished and the pronounced ECT effect persisted over the subsequent 24-week period of observation.

CONCLUSION

To our knowledge, this is the first clinical report on the efficacy of ECT for treating pain associated with BMS. ECT can be considered to be an option for treating individuals with enduring and intractable intraoral burning pain.

Serum levels of P-selectin in men with high-functioning autism

Immune dysfunction has been proposed as a mechanism for the pathophysiology of autistic-spectrum disorders. The selectin family of adhesion molecules plays a prominent role in immune/inflammatory responses. We determined the serum levels of three types of soluble-form selectin (sP, sL and sE) in 15 men with high-functioning autism and 22 age-matched healthy controls by enzyme-linked immunosorbent assay. Levels of sP-selectin and sL-selectin were significantly lower in patients than in controls. Furthermore, sP-selectin levels were negatively correlated with impaired social development during early childhood.