Self-energy on the low- to high-energy electronic structure of correlated metal SrVO3.

The correlated electronic structure of SrVO(3) has been investigated by angle-resolved photoemission spectroscopy using in situ prepared thin films. Pronounced features of band renormalization have been observed: a sharp kink ∼60 meV below the Fermi level (E(F)) and a broad so-called "high-energy kink" ∼0.3 eV below E(F) as in the high-T(c) cuprates, although SrVO(3) does not show magnetic fluctuations. We have deduced the self-energy in a wide energy range by applying the Kramers-Kronig relation to the observed spectra. The obtained self-energy clearly shows a large energy scale of ∼0.7 eV, which is attributed to electron-electron interaction and gives rise to the ∼0.3 eV kink in the band dispersion as well as the incoherent peak ∼1.5 eV below E(F). The present analysis enables us to obtain a consistent picture for both the incoherent spectra and the band renormalization.

Resonant tunneling driven metal-insulator transition in double quantum-well structures of strongly correlated oxide.

The metal-insulator transition (MIT), a fascinating phenomenon occurring in some strongly correlated materials, is of central interest in modern condensed-matter physics. Controlling the MIT by external stimuli is a key technological goal for applications in future electronic devices. However, the standard control by means of the field effect, which works extremely well for semiconductor transistors, faces severe difficulties when applied to the MIT. Hence, a radically different approach is needed. Here, we report an MIT induced by resonant tunneling (RT) in double quantum well (QW) structures of strongly correlated oxides. In our structures, two layers of the strongly correlated conductive oxide SrVO3 (SVO) sandwich a barrier layer of the band insulator SrTiO3. The top QW is a marginal Mott-insulating SVO layer, while the bottom QW is a metallic SVO layer. Angle-resolved photoemission spectroscopy experiments reveal that the top QW layer becomes metallized when the thickness of the tunneling barrier layer is reduced. An analysis based on band structure calculations indicates that RT between the quantized states of the double QW induces the MIT. Our work opens avenues for realizing the Mott-transistor based on the wave-function engineering of strongly correlated electrons.

Association of the HLA-DPB1*0501 allele with anti-aquaporin-4 antibody positivity in Japanese patients with idiopathic central nervous system demyelinating disorders.

There are two subtypes of multiple sclerosis (MS) in Asians: the opticospinal (OSMS) form that shows a selective involvement of the optic nerve and the spinal cord and the conventional (CMS) form that has disseminated lesions in the central nervous system including the cerebrum, cerebellum and brainstem. Both show distinct human leukocyte antigen (HLA) class II associations. OSMS has similar features to the relapsing form of neuromyelitis optica (NMO) in Western populations. Recently, it was shown that antibodies to aquaporin-4 (AQP4) are specifically detected in NMO patients and in some Japanese patients with OSMS or recurrent optic neuritis or myelitis. To clarify the immunogenetic background of anti-AQP4 antibody production, we studied HLA-DRB1 and -DPB1 gene polymorphisms in anti-AQP4 antibody-positive and -negative patients with idiopathic demyelinating diseases, such as MS, recurrent optic neuritis and recurrent myelitis. The phenotypic frequency of the HLA-DPB1*0501 allele was significantly increased in anti-AQP4 antibody-positive patients (89.5%, odds ratio = 4.8; 95% confidence interval = 1.6-14.3, n = 38, P(corr) = 0.032) compared with controls (64.0%, n = 125) but not in either anti-AQP4 antibody-negative OSMS (75.0%, n = 32) or CMS (69.2%, n = 52) patients. There was no significant correlation between any HLA-DRB1 allele and the existence of anti-AQP4 antibody. These findings suggest that the emergence of anti-AQP4 antibody is reinforced by the presence of the HLA-DPB1*0501 allele in Japanese.

Dielectric collapse at the LaAlO3/SrTiO3 (001) heterointerface under applied electric field.

The fascinating interfacial transport properties at the LaAlO3/SrTiO3 heterointerface have led to intense investigations of this oxide system. Exploiting the large dielectric constant of SrTiO3 at low temperatures, tunability in the interfacial conductivity over a wide range has been demonstrated using a back-gate device geometry. In order to understand the effect of back-gating, it is crucial to assess the interface band structure and its evolution with external bias. In this study, we report measurements of the gate-bias dependent interface band alignment, especially the confining potential profile, at the conducting LaAlO3/SrTiO3 (001) heterointerface using soft and hard x-ray photoemission spectroscopy in conjunction with detailed model simulations. Depth-profiling analysis incorporating the electric field dependent dielectric constant in SrTiO3 reveals that a significant potential drop on the SrTiO3 side of the interface occurs within ~2 nm of the interface under negative gate-bias. These results demonstrate gate control of the collapse of the dielectric permittivity at the interface, and explain the dramatic loss of electron mobility with back-gate depletion.

Tc1/Tc2 and Th1/Th2 balance in Asian and Western types of multiple sclerosis, HTLV-I-associated myelopathy/tropical spastic paraparesis and hyperIgEaemic myelitis.

CD8+ T cells, like CD4+ T cells, can differentiate into at least two subsets with distinct cytokine patterns: Tc1 cells produce Th1-like cytokines and Tc2 cells produce Th2-like cytokines. To clarify the immunopathological roles of Tc1 and Tc2 cells in central nervous system (CNS) inflammation, we examined intracellular cytokines in CD8+ and CD4+ T cells by flow cytometry and analyzed the Tc1/Tc2 balance as well as the Th1/Th2 balance in 80 patients with various CNS inflammatory diseases, including 20 with optico-spinal multiple sclerosis (OS-MS), 21 with conventional MS (C-MS), 22 with human T-lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and 17 with hyperIgEaemic myelitis. Twenty-two healthy subjects were also examined as controls. Patients with OS-MS showed a significantly higher percentage of INF-gamma+IL-4- CD8+ T cells as well as CD4+ T cells and a significantly higher intracellular interferon-gamma (IFN-gamma)/interleukin-4 (IL-4) ratio both in CD8+ and CD4+ T cells throughout the relapse and remission phases than the healthy controls. Furthermore, the patients with OS-MS showed a significantly lower percentage of INF-gamma-IL-4+ CD4+ T cells as well as CD8+ T cells during the relapse phase than the healthy controls. On the other hand, the patients with C-MS showed a significantly higher percentage of IFN-gamma-IL-4+ CD8+ T cells in addition to more IFN-gamma+IL-4- CD4+ T cells during the relapse phase than the healthy controls. The HAM/TSP patients showed a significantly higher percentage of INF-gamma+IL-4- CD8+ T cells and a significantly higher intracellular IFN-gamma/IL-4 ratio in CD8+ T cells than the healthy controls. In contrast, in hyperIgEaemic myelitis, in addition to a significantly lower intracellular IFN-gamma/IL-4 ratio in CD4+ T cells, a tendency toward a lower intracellular IFN-gamma/IL-4 ratio in CD8+ T cells in comparison to the healthy controls was observed. These results clarified for the first time the distinct Tc1/Tc2 balance in each disease condition as follows: Tc1 cell response is predominant in OS-MS and HAM/TSP, while Tc2 cell response is predominant in hyperIgEaemic myelitis and at relapse phase of C-MS. Furthermore, our results suggest that CD8+ T cells play an adjunctive role in disease induction and the clinical course of MS.

Th2 shift in mononeuritis multiplex and increase of Th2 cells in chronic inflammatory demyelinating polyneuropathy: an intracellular cytokine analysis.

To elucidate the T helper 1 (Th1)/T helper 2 (Th2) balance in various inflammatory neuropathies, we measured the ratio of intracellular interferon-gamma (IFN-gamma)-positive to IL-4-positive cells (intracellular IFN-gamma/IL-4 ratio) by flow cytometry in peripheral blood CD4(+) T cells of 14 patients with mononeuritis multiplex (MNM), 12 patients with chronic inflammatory demyelinating polyneuropathy (CIDP), 10 patients with Guillain-Barré syndrome (GBS), 23 patients with neurodegenerative disorders and 36 healthy controls by intracellular labeling. The patients with MNM showed a significantly lower intracellular IFN-gamma/IL-4 ratio (P<0.05) and higher IL-4(+)/IFN-gamma(-) cell percentages (P<0.05) than the controls. The increase of IL-4(+)/IFN-gamma(-) cell percentages was especially prominent in MNM of unknown etiology (P<0.005). The patients with CIDP also showed significantly higher IL-4(+)/IFN-gamma(-) cell percentages (P<0.05) than the controls. The IL-4(+)/IFN-gamma(-) cell percentages were increased in some patients with GBS, but the difference was not significant compared with the controls. Thus, our results suggest that a Th2 shift is a characteristic of MNM and may play an important role in the development of the disease.

Flow cytometric differentiation of Asian and Western types of multiple sclerosis, HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and hyperIgEaemic myelitis by analyses of memory CD4 positive T cell subsets and NK cell subsets.

We examined the alterations of memory CD4(+) T cell subsets bearing surface receptors linked to either Th1 or Th2 cytokine production as well as natural killer (NK) cell subsets by three color flow cytometry in the peripheral blood from 36 patients with clinically definite multiple sclerosis (MS), 27 patients with HAM/TSP, 13 patients with hyperIgEaemic myelitis who had mite antigen-specific IgE and 25 healthy controls (HC). The patients with MS were clinically classified into an optico-spinal form of MS (Asian type, MS-A) and the conventional form of MS (Western type, MS-W). MS-A showed a significant increase of CD4(+)CD45RA(-)CCR5(+) cells (Th1 cells) through the relapse and remission phases in comparison to HC, while MS-W showed a significant increase of CD4(+)CD45RO(+)CD62L(-) cells (Th1 cells) only at the relapse phase. HAM/TSP showed a significant increase of CCR5(+) and CD62L(-) memory CD4(+) T cells as well as CD30(+) memory CD4(+) T cells (Th2 cells) in comparison to HC. On the other hand, a selective increase of CD4(+)CD45RO(+)CD30(+) cells was found in hyperIgEaemic myelitis. The percentage of mature NK cells (CD3(-)CD16(+)CD56(+) cells) as well as double negative T cells (CD3(+)CD4(-)CD8(-) cells) decreased significantly in HAM/TSP in comparison to HC. Our findings therefore suggest a flow cytometric analysis of Th1/Th2-associated markers on memory CD4(+) T cells as well as NK cell subsets to be useful for differentiating various inflammatory neurologic conditions.

Th1 dominance in HAM/TSP and the optico-spinal form of multiple sclerosis versus Th2 dominance in mite antigen-specific IgE myelitis.

To clarify the Th1/Th2 balance in spinal cord inflammation, we used ELISA to measure the total and allergen-specific IgE in 69 patients with clinically definite multiple sclerosis (MS), including 24 patients with the optico-spinal form of MS, 45 with HAM/TSP, 30 HTLV-I carriers without HAM/TSP, 40 patients with acute myelitis, 43 with neurodegenerative disorders, and 42 healthy subjects, and flow cytometry to study the intracellular IFNgamma-positive versus IL-4-positive cell ratio (intracellular IFNgamma/IL-4 ratio) in peripheral blood CD4(+) T cells in 40 patients with MS, including 17 patients with the optico-spinal form of MS, 23 with HAM/TSP, 22 with acute myelitis, 23 with neurodegenerative disorders, and 36 healthy subjects. Patients with HAM/TSP showed a significantly higher intracellular IFNgamma/IL-4 ratio, lower IL-4(+)/IFN-gamma(-) cell percentages, lower total IgE level, and lower frequency of cedar pollen-specific IgE than did the controls. The patients with optico-spinal MS showed a significantly higher intracellular IFNgamma/IL-4 ratio and higher IL-4(-)/IFN-gamma(+) cell percentages than the controls even at remission or in the convalescence phase. In contrast, in the patients with acute myelitis, the total serum IgE level and the frequency of mite antigen-specific IgE were significantly elevated in comparison to the controls, while those having mite antigen-specific IgE myelitis showed a significantly lower IFNgamma/IL-4 ratio in the CD4(+) T cells in comparison to the controls. These findings suggest that the Th1 cell response is predominant in HAM/TSP and optico-spinal MS, whereas the Th2 cell response is predominant in mite antigen-specific IgE myelitis.

Heightened IgE response to mite antigens in inflammatory neuropathies.

In order to clarify the IgE response to common environmental antigens, we measured the serum total IgE and allergen-specific IgE in 50 patients with Guillain-Barré syndrome (GBS), nine patients with Fisher syndrome (FS), 14 patients with chronic inflammatory demyelinating polyneuropathy (CIDP), 18 patients with mononeuritis multiplex (MNM), 43 patients with neurodegenerative disorders and 82 healthy controls by ELISA. The total IgE level was significantly higher in patients with GBS (median = 135 U/ml, P<0.05), CIDP (median = 175 U/ml, P<0.05) and MNM (median= 199 U/ml, P<0.05), than in the healthy controls (median = 79 U/ml), but not in those patients with neurodegenerative disorders. The specific IgE to Dermatophagoides pteronyssinus was significantly higher in the patients with GBS (56%, P<0.01) and MNM (72%, P<0.005) than in the healthy controls (32%). The level of specific IgE to Dermatophagoides farinae tended to be higher in the patients with GBS than in the healthy controls (0.05

Quantitation of serum carotenoid concentrations in healthy inhabitants by high-performance liquid chromatography.

Serum carotenoid concentrations in healthy subjects by age and sex were investigated, as determined by two high-performance liquid chromatography (HPLC) methods. Serum 'carotene' concentrations were 0.655 +/- 0.499 mumol/l 35.2 +/- 26.8 micrograms/dl) for 227 males, and 1,395 +/- 0.780 mumol/l (74.9 +/- 41.9 micrograms/dl) for 370 females. In addition, serum concentrations of alpha-carotene, beta-carotene, and lycopene were obtained from another sample included 356 males and 567 females living in the same area. alpha-Carotene for 356 males was 0.085 +/- 0.096 mumol/l (4.6 +/- 5.2 micrograms/dl), beta-carotene was 0.555 +/- 0.491 mumol/l (29.8 +/- 26.4 micrograms/dl), and lycopene was 0.372 +/- 0.273 mumol/l (20.0 +/- 14.7 micrograms/dl), respectively. Serum concentrations of alpha-carotene, beta-carotene as well as concentrations of lycopene in these inhabitants were significantly higher for females than for males (p less than 0.001).

Hyperprolactinemia in optico-spinal multiple sclerosis.

OBJECTIVE: To clarify the clinical features of MS patients with hyperprolactinemia. SUBJECTS AND METHODS: The serum prolactin level was measured in 67 Japanese patients (19 men and 48 women) with multiple sclerosis (MS) and in 16 patients (4 men and 12 women) with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) using a two-site immunoradiometric assay. RESULTS: In the MS patients, 32 were classified as having Asian type MS showing a selective involvement of the optic nerves and spinal cord, while the other 35 were classified as having Western type MS which displayed disseminated central nervous system involvement. In women, the serum prolactin level was found to be significantly higher only in Asian type MS (mean=23.1 ng/ml, n=25) than in HAM/TSP (mean=6.9 ng/ml, n=12) (p=0.0297), while it did not differ significantly in men among the three groups. Hyperprolactinemia was significantly associated with acute relapse involving the optic nerves. All MS patients with hyperprolactinemia (7 women with Asian type MS and 2 women with Western type MS) showed recurrent opticomyelitis either throughout or in the early course of the disease, and also had a higher age of onset, a higher Expanded Disability Status Scale score, a greater visual impairment, and higher cell counts and protein contents in the cerebrospinal fluid than did the normoprolactinemic patients. CONCLUSION: Hyperprolactinemia may be one of the characteristic features of Asian patients with MS who preferentially show the optic nerve involvement.

Effects of bathing in hot water on portal hemodynamics in healthy subjects and in patients with compensated liver cirrhosis.

Bathing in hot water induces vasodilatation of the peripheral vessels and alteration of blood distribution. Using a Doppler flowmeter, we evaluated the effect of bathing in hot water on portal hemodynamics. Eight controls and 8 patients with compensated liver cirrhosis remained immersed in hot water at 42 degrees C for 5 minutes. Portal flow significantly decreased from 811 +/- 141 (ml/min) at the baseline to 530 +/- 98 in the controls and from 855 +/- 308 to 642 +/- 208 in cirrhotics immediately after bathing. This decrease (25%) in cirrhotics was significantly less than that (35%) in controls because vessel diameter did not decrease as rapidly as it did in controls. Portal flow after 30 minutes returned to the baseline values in controls but remained low in cirrhotics. These findings suggest that cirrhotics have a lower hemodynamic response to bathing in hot water compared with that in controls.

Myelitis associated with atopic disorders in Japan: a retrospective clinical study of the past 20 years.

OBJECTIVE: To clarify the clinical features of myelitis associated with atopic disorders in Japanese patients. SUBJECTS AND METHODS: We retrospectively studied the clinical, immunological and electrophysiological features of 68 consecutive patients with myelitis of acute or subacute onset diagnosed at Kyushu University Hospital during the past 20 years. RESULTS: While only 2 of 28 (7%) patients with myelitis diagnosed between 1979 and 1993 had either atopic dermatitis (AD) or bronchial asthma (BA), 19 of 40 (48%) patients with myelitis diagnosed between 1994 and 1998 did. Among the 40 patients with myelitis diagnosed between 1994 and 1998, 19 patients with either AD or BA as well as 21 patients without either disease showed a significantly higher level of serum total IgE, higher frequency of hyperIgEaemia and higher frequency of mite antigen-specific IgE than 82 healthy controls. Myelitis patients with AD presenting as persistent paresthesia/dysesthesia in all four limbs showed cervical cord lesions on MRI and abnormalities in upper limb motor evoked potentials but no abnormalities in the cerebrospinal fluid (CSF), while myelitis patients with BA showed preferential involvement of the lower motor neurons clinically and electromyographically. In addition, 12 patients with myelitis who had hyperIgEaemia and mite antigen-specific IgE but neither AD nor BA showed incomplete transverse myelitis with mild motor disability and few CSF abnormalities. CONCLUSION: The clinical features of myelitis associated with atopic disorders were in part distinguished by the type of preceding atopic disorder, and also were different from those of hyperIgEaemic myelitis with no preceding atopic disorders.

[A case of orbital myositis with blepharoptosis demonstrating the swelling of superior levator palpebrae muscle on magnetic resonance images].

A 51-year-old woman developed diplopia and left blepharoptosis with an insidious onset. On orbital MRI, the extraocular and a left superior levator palpebrae muscles were swollen and enhanced by gadolinium, suggesting orbital myositis. The left blepharoptosis was improved two weeks and the swelling of superior levator palpebrae muscle one month after prednisolone administration. This is the first report that the lesion of superior levator palpebrae muscle was demonstrated by MRI in orbital myositis.

Effects of alcohol drinking and cigarette smoking on serum alpha- and beta-carotene concentrations in healthy adults.

The effects of alcohol and cigarette consumption on serum concentrations of alpha-carotene and beta-carotene in 312 healthy male adults, aged from 20 to 58 years, were investigated. Serum concentrations of beta-carotene were lower in alcohol drinkers (17.8 micrograms/dl; 0.33 mumol/l) than in nondrinkers (23.2 micrograms/dl; 0.43 mumol/l). Serum concentrations of alpha- and beta-carotenes were higher in nonsmokers (alpha-carotene: 7.4 micrograms/dl; beta-carotene: 22.6 micrograms/dl) than in current smokers (alpha-carotene: 5.9 micrograms/dl; beta-carotene: 18.4 micrograms/dl). In simple correlation and multiple regression analyses, smoking, smoking and alcohol drinking were inversely correlated with serum concentrations of alpha- and beta-carotenes in healthy adults. In contrast, serum concentrations of alpha- and beta-carotenes rose significantly with an increasing intake frequency of green-yellow vegetables or fruits. In addition, the effect of alcohol drinking on the serum beta-carotene concentration was more pronounced that that of smoking.

[A study of taste-sensitivity in pre-school children with special reference to its time-course according to their growth].

Sensitivity to drops of sweet, salty, sour and bitter tasting test liquids was evaluated in 47 kindergarteners (20 males, 27 females). The results revealed that ability for taste discrimination in pre-school children was related to growth and development processes, and was strongly affected by environmented factors mainly dietary lifestyle. Pre-school children showed no sex difference in sensitivity to these 4 kinds of tastes, but displayed gradually increasing sensitivity to sweet and salty tastes from age 3, 4 to 5 on, and gradually decreasing sensitivity to sour taste, while no age-related change was found with regard to bitter taste. Examination of its relationship to dietary habits revealed that taste discrimination became gradually sensitive and to a greater extent at age 3 to 5 for the group that was more careful with weaning and current diets and the group with some family member(s) practicing therapeutic diet treatment, compared with other groups.

[A study on the relationship of taste-sensitivity to salt-restriction in adults].

A survey of the extent of the practice of salt-restriction, duration of such salt restriction, and the ability to discriminate between different degrees of salt content, was performed in a town located in Tottori prefecture Subjects were 20 families (55 persons) where both parents and their adult children had a previous history of hypertension, 38 families (111 persons) where either or both parents had a previous history of hypertension, and 33 families (99 persons) where both parents and their adult children had no history of hypertension. Sensitivity to salt-taste and the relation between the practice of salt-restriction and sensitivity to salt-taste were analyzed. The results are summarized as follows: 1. For persons with histories of hypertension current practice of salt-restriction was significantly greater degree of preference for salt-taste was lower, and the duration of salt-restriction period was longer than those persons without a history of hypertension. 2. Families where both parents and their adult children had histories of hypertension had the highest percentage of these practicing salt-restriction and the largest representation of those who practiced it for a long duration. 3. Those who restricted salt use for a long time also showed a low preference for salt-taste. 4. The sensitivity to salt-taste was much higher in persons who had histories of hypertension than others. 5. Sensitivity to salt-taste was much higher in families where both parents and their adult children had histories of hypertension than others. 6. In families where both parents and adult children had histories of hypertension, significant relationship were observed between parents and their adult children and between husbands and wives in sensitivity to salt-taste.(ABSTRACT TRUNCATED AT 250 WORDS)

High-dose vitamin C therapy for inclusion body myositis.

OBJECTIVES: The efficiency of high-dose vitamin C therapy for inclusion body myositis (IBM) was assessed. SUBJECTS & METHODS: The subjects were five patients with IBM confirmed pathologically. After the intravenous administration of 40 mg/kg vitamin C five times/week for four weeks, muscle weakness was found to improve in three cases. The average muscle score improved from 8.1 to 8.8, from 7.0 to 8.1 and from 6.2 to 6.8. Magnetic resonance imaging (MRI) demonstrated a reduction in the size of T2 high lesions and gadolinium enhancement in the thigh muscles in one case. Based on our findings, high-dose vitamin C therapy is considered to be effective in some cases of IBM.