Mean structure of the supercritical turbulent spiral in Taylor-Couette flow

The large-scale laminar/turbulent spiral patterns that appear in the linearly unstable regime of counter-rotating Taylor-Couette flow are investigated from a statistical perspective by means of direct numerical simulation. Unlike the vast majority of previous numerical studies, we analyse the flow in periodic parallelogram-annular domains, following a coordinate change that aligns one of the parallelogram sides with the spiral pattern. The domain size, shape and spatial resolution have been varied and the results compared with those in a sufficiently large computational orthogonal domain with natural axial and azimuthal periodicity. We find that a minimal parallelogram of the right tilt significantly reduces the computational cost without notably compromising the statistical properties of the supercritical turbulent spiral. Its mean structure, obtained from extremely long time integrations in a co-rotating reference frame using the method of slices, bears remarkable similarity with the turbulent stripes observed in plane Couette flow, the centrifugal instability playing only a secondary role. This article is part of the theme issue 'Taylor-Couette and related flows on the centennial of Taylor's seminal Philosophical transactions paper (Part 2)'.

Development of matured hiPSCs-derived 3D cardiac tissue using ERR gamma agonist and mechanical stress and application for Hypertrophic Cardiomyopathy (HCM) model

Introduction

Tissue engineering using human induced pluripotent stem cells-derived cardiomyocytes (hiPSCs-CMs) is one of the potential tools to replicate human heart in vitro. Although there are many publications on 3 dimensional (3D) heart tissues (1), these tissues show fetal like phenotypes. For that reason, several maturation methods such as electrical stimulation and mechanical stress have been investigated (2, 3). However, these methods have been inadequate in differentiating fetal like phenotype tissue from adult tissues. Previously, we identified a novel compound, T112, which induced hiPSCs-CMs maturation from approximately 9,000 compounds using Troponin I1-EmGFP and Troponin I3-mCherry double reporter hiPSCs-CMs. This compound enhanced morphological and metabolic maturation of hiPSCs-CMs via estrogen-rerated receptor gamma activation

Purpose

We hypothesized that our novel compound, T112, in combination with mechanical stress could result in further maturation of 3D heart tissue. Therefore, our specific aim is to develop a novel maturation method applicable to genetic disease model of HCM using 3D heart tissue combined with T112.

Methods

We constructed 3D heart tissue mixed with fibroblast and double reporter hiPSCs-CMs by the hydrogel methods using Flex cell system®. We added T112 with or without mechanical stretching to 3D tissue from 7 to 15 days after 3D heart tissue was constructed. Then we measured maturation related phenotype such as sarcomere gene expression, mitochondrial DNA content and cell size.

Results

Similar to hiPSCs-CM, the addition of T112 to the constructed 3D heart tissue significantly increased TNNI3 mRNA compared to that of DMSO. Furthermore, T112 treated 3D heart tissue showed increased cell size and oblong shape. Next, in order to promote more maturation of 3D heart tissue, we performed mechanical stretching with the addition of T112. The combination of T112 with mechanical stretching showed higher expression of mCherry, a reporter protein for TNNI3 expression, and higher isotropy of sarcomere alignment in 3D heart tissue than that with the static condition. Furthermore, 3D heart tissue in the treatment of T112 with or without mechanical stretching showed higher mitochondrial DNA content compared to the respective DMSO controls. Interestingly, we applied this combination method to hiPSCs carrying MYH7 R719Q mutation which is known to cause hypertrophic cardiomyopathy, and the 3D heart tissue composed of cardiomyocytes derived from mutant iPSCs demonstrated increased sarcomere disarray compared to isogenic wild-type 3D heart tissue.

Conclusion

These results suggest that the combination of T112 and mechanical stretching promotes metabolic and structural maturation of 3D heart tissue and would be useful for creating a HCM disease model.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): T-CiRA project, Takeda Pharmaceutical Company Limited

Anticoagulant Activity in Cell Homogenate of Adult T Cell Leukemia

The hemostatic abnormality in 18 patients with adult T cell leukemia (ATL) was studied. Activated partial thromboplastin time (APTT) was slightly prolonged and prekallikrein activity was markedly low in these patients. The leukemic cell homogenate from these patients prolonged the recalcification time (RCT) of normal plasma; homogenates containing more than 3 ×103 cells/μi prolonged it, although a lower cell concentration shortened it. The crude anticoagulant fraction from the gel filtration, with a molecular weight of about 34,000, prolonged RCT. The crude anticoagulant did not affect prothrombin time (PT), thrombin activity or activated X activity at any concentration, but prolonged the contact activation test, inhibited the activation of prekallikrein and prolonged RCT of Fletcher trait, Fitzgerald trait and F XII deficient plasma. These effects of ATL cell homo-genate were stronger on platelet poor plasma than on platelet rich plasma. Although ATL cells had low procoagulant activity, increase of leukemic cells made anticoagulant activity predominant, might be the cause of hemostatic abnormality or amplify the bleeding tendency in patients with ATL.

The relationship between free-stream coherent structures and near-wall streaks at high Reynolds numbers

The present work is based on our recent discovery of a new class of exact coherent structures generated near the edge of quite general boundary layer flows. The structures are referred to as free-stream coherent structures and were found using a large Reynolds number asymptotic approach to describe equilibrium solutions of the Navier-Stokes equations. In this paper, first we present results for a new family of free-stream coherent structures existing at relatively large wavenumbers. The new results are consistent with our earlier theoretical result that such structures can generate larger amplitude wall streaks if and only if the local spanwise wavenumber is sufficiently small. In a Blasius boundary layer, the local wavenumber increases in the streamwise direction so the wall streaks can typically exist only over a finite interval. However, here it is shown that they can interact with wall curvature to produce exponentially growing Görtler vortices through the receptivity process by a novel nonparallel mechanism. The theoretical predictions found are confirmed by a hybrid numerical approach. In contrast with previous receptivity investigations, it is shown that the amplitude of the induced vortex is larger than the structures in the free-stream which generate it.This article is part of the themed issue 'Toward the development of high-fidelity models of wall turbulence at large Reynolds number'.

HLA-G1, but Not HLA-G3, Suppresses Human Monocyte/Macrophage-mediated Swine Endothelial Cell Lysis

The inhibitory function of HLA-G1, a class Ib molecule, on monocyte/macrophage-mediated cytotoxicity was examined. The expression of inhibitory receptors that interact with HLA-G, immunoglobulin-like transcript 2 (ILT2), ILT4, and KIR2DL4 (CD158d) on in vitro-generated macrophages obtained from peripheral blood mononuclear cells and the phorbol 12-myristate 13-acetate (PMA)-activated THP-1 cells were examined by flow cytometry. cDNAs of HLA-G1, HLA-G3, HLA-E, and human β2-microglobulin were prepared, transfected into pig endothelial cells (PECs), and macrophage- and the THP-1 cell-mediated PEC cytolysis was then assessed. In vitro-generated macrophages expressed not only ILT2 and ILT4 but CD158d as well. The transgenic HLA-G1 on PEC indicated a significant suppression in macrophage-mediated cytotoxicity, which was equivalent to that of transgenic HLA-E. HLA-G1 was clearly expressed on the cell surface of PEC, whereas the levels of HLA-G3 were much lower and remained in the intracellular space. On the other hand, the PMA-activated THP-1 cell was less expressed these inhibitory molecules than in vitro-generated macrophages. Therefore, the HLA-G1 on PECs showed a significant but relatively smaller suppression to THP-1 cell-mediated cytotoxicity compared to in vitro-generated macrophages. These results indicate that by generating HLA-G1, but not HLA-G3, transgenic pigs can protect porcine grafts from monocyte/macrophage-mediated cytotoxicity.

Studies of Pig Complement: Measurement of Pig CH50, ACH50, and Components

BACKGROUND

On the basis of a comparison of the hemolytic complement titer in pigs with that in humans, the complement system of pigs was investigated. The response of innate immunity, such as the natural antibodies, against humans was also examined.

METHODS

Hemolytic complement activity of pig serum was measured with the use of a microtitration technique. CH50 was determined according to the method of Mayer. ACH50 was assayed according to the methods of Platts-Milles and Ishizaka. Hemolytic activities of C1, C4, C2, C3, C5, C8, and C9 were estimated through the use of intermediate cells and reagents, as described previously. In addition, the pig natural anti-human antibody was studied with the use of human peripheral blood mononuclear cells (PBMCs). Human PBMCs were stained with 5% pig serum, followed by staining with fluorescein isothiocyanate-labeled goat anti-pig IgG and IgM. The resulting stained cells were quantified by use of a FACScalibur system. The alternative pathway of pig complement was also measured with the use of human erythrocytes and normal pooled pig serum with or without Mg(++)EGTA.

RESULTS

Both the CH50 and ACH50 titers were lower than those of humans. Concerning the components, except for C3, each component, that is, C1, C4, C2, C5, C8, and C9, was also lower than that of humans, based on measured values for human complement components. Pig serum clearly contains natural antibodies, IgG and IgM, to human PBMCs. The alternative pathway of pig complement reacted with human erythrocytes.

CONCLUSIONS

As a whole, pig innate immunity, the complement system and natural antibody, recognizes the surfaces of human cells.

'PrP systemic deposition disease': clinical and pathological characteristics of novel familial prion disease with 2-bp deletion in codon 178

BACKGROUND AND PURPOSE

A novel TYPE of prion disease associated mainly with autonomic-sensory polyneuropathy was reported by us previously.

METHODS

Here the autopsy pathology for patient 1 (the sister) and the clinical characteristics of her younger brother (patient 2) are newly reported. Polymerase chain reaction based restriction fragment length polymorphism analysis of the prion protein gene (PRNP) was performed on both patients and their father (normal control).

RESULTS

Polymerase chain reaction based restriction fragment length polymorphism analysis revealed a 2-bp deletion (CT) in codon 178 that causes an additional variable 25 amino acids at the C terminal, from the mutation site to the premature stop codon at codon 203, in both patients 1 and 2 but not in their father. The autopsy of patient 1 showed remarkable prion protein (PrP) deposits in the sympathetic ganglion and peripheral nerves, correlated to her severe autonomic sensory failure. PrP deposits were also found in the central nervous system and peripheral organs such as the heart, lung, stomach, jejunum, ileum, colon, urinary bladder and adrenal gland. The symptoms and biopsy findings of patient 2 were nearly the same as those reported previously for patient 1. His cognitive function was well preserved, but autonomic functions were severely impaired. His biopsied samples showed PrP deposits in the sural nerve and nerve plexuses of the stomach and colon.

CONCLUSION

The present unique 2-bp deletion (CT) in codon 178 induced a 'PrP systemic deposition disease' such as pan-autonomic failure, sensory neuropathy and mild cognitive impairment with a specific pathology.

Human HLA-Ev (147) Expression in Transgenic Animals

BACKGROUND

In our previous study, we reported on the development of substituting S147C for HLA-E as a useful gene tool for xenotransplantation. In this study we exchanged the codon of HLA-Ev (147), checked its function, and established a line of transgenic mice.

METHODS

A new construct, a codon exchanging human HLA-Ev (147) + IRES + human beta 2-microgloblin, was established. The construct was subcloned into pCXN2 (the chick beta-actin promoter and cytomegalovirus enhancer) vector. Natural killer cell- and macrophage-mediated cytotoxicities were performed using the established the pig endothelial cell (PEC) line with the new gene. Transgenic mice with it were next produced using a micro-injection method.

RESULTS

The expression of the molecule on PECs was confirmed by the transfection of the plasmid. The established molecules on PECs functioned well in regulating natural killer cell-mediated cytotoxicity and macrophage-mediated cytotoxicity. We have also successfully generated several lines of transgenic mice with this plasmid. The expression of HLA-Ev (147) in each mouse organ was confirmed by assessing the mRNA. The chick beta-actin promoter and cytomegalovirus enhancer resulted in a relatively broad expression of the gene in each organ, and a strong expression in the cases of the heart and lung.

CONCLUSION

A synthetic HLA-Ev (147) gene with a codon usage optimized to a mammalian system represents a critical factor in the development of transgenic animals for xenotransplantation.

Disseminated Metastatic Tissue Calcification After Orthotopic Liver Transplantation: A Case Report

BACKGROUND

Hypercalcemia has been observed in patients after liver transplantation. However, it is rare that the hypercalcemia induced disseminated tissue calcification and heart failure.

CASE REPORT

We report a rare case of heart failure caused by disseminated metastatic tissue calcification that involved extensive progressive myocardial calcification after liver transplantation. A 20-year-old man with end-stage liver disease due to biliary atresia underwent ABO-incompatible living donor liver transplantation. After successful transplantation, he suffered from antibody-mediated rejection. Subsequently, ABO-matched cadaveric liver retransplantation was successfully performed. Hypercalcemia developed gradually following the second transplantation. His serum calcium level increased to 18.3 mg/dL with sudden onset of ventricular tachycardia. Although he was resuscitated with a cardiopulmonary support device, he died of heart and liver failure. Histopathologic examination revealed systemic disseminated metastatic tissue calcification, including massive myocardial calcification.

CONCLUSION

Progressive worsening of hypercalcemia resulted in disseminated metastatic tissue calcification and massive metastatic myocardial calcification, which led to heart failure after liver transplantation. Because hypercalcemia after liver transplantation can cause fatal tissue calcification, early intervention for hypercalcemia should be considered.

Cognitive and affective functions in Alzheimer's disease patients with metabolic syndrome

BACKGROUND AND PURPOSE

The influence of metabolic syndrome (MetS) on cognitive and affective functions in patients with Alzheimer's disease (AD) was examined.

METHODS

A total of 570 AD patients were divided into two subgroups depending on waist circumference (WC) (normal versus achieving Japanese diagnostic criteria of MetS). Afterwards, the AD control subgroup was defined as those normal WC patients with no vascular risk factors (VRFs). The AD with MetS (AD-MetS) subgroup was defined as the MetS WC group who had two or more VRFs to qualify as having MetS. Cognitive and affective functions, insulin resistance, vascular endothelial function and white matter changes between AD-MetS and AD controls were compared.

RESULTS

Scores on the Mini-Mental State Examination, Hasegawa Dementia Score-Revised, Frontal Assessment Battery and Montreal Cognitive Assessment were worse in the AD-MetS group than in AD controls, but the difference was not significant. Some analyses were conducted twice, once including all patients and once including only late-elderly patients. Scores on the Geriatric Depression Scale were found to be significantly higher for AD-MetS than for AD controls (all ages, late-elderly), as were those for apathy (late-elderly). Furthermore, both the homeostasis model assessment of insulin resistance and reactive hyperemia index scores were significantly worse in AD-MetS than in AD controls, whilst white matter changes showed a tendency to be worse.

CONCLUSIONS

Greater cognitive and affective decline occurs in patients with AD-MetS than in those without. Further, insulin resistance and vascular endothelial dysfunction are strongly correlated with AD-MetS before pathological white matter changes can be observed.

Pressure-dependent magnetization and magnetoresistivity studies on tetragonal FeS (mackinawite): revealing its intrinsic metallic character

The transport and magnetic properties of the tetragonal Fe[Formula: see text]S were investigated using magnetoresistivity and magnetization within [Formula: see text] K, [Formula: see text] 70 kOe and [Formula: see text] 3.0 GPa. In addition, room-temperature x-ray diffraction and photoelectron spectroscopy were also applied. In contrast to previously reported nonmetallic character, Fe[Formula: see text]S is intrinsically metallic but due to a presence of a weak localization such metallic character is not exhibited below room temperature. An applied pressure reduces strongly this additional resistive contribution and as such enhances the temperature range of the metallic character which, for ∼3 GPa, is evident down to 75 K. The absence of superconductivity as well as the mechanism behind the weak localization will be discussed.

Canonical exact coherent structures embedded in high Reynolds number flows

The applications and implications of two recently addressed asymptotic descriptions of exact coherent structures in shear flows are discussed. The first type of asymptotic framework to be discussed was introduced in a series of papers by Hall & Smith in the 1990s and was referred to as vortex-wave interaction theory (VWI). New results are given here for the canonical VWI problem in an infinite region; the results confirm and extend the results for the infinite problem inferred the recent VWI computation of plane Couette flow. The results given define for the first time exact coherent structures in unbounded flows. The second type of canonical structure described here is that recently found for asymptomatic suction boundary layer and corresponds to freestream coherent structures (FCS), in boundary layer flows. Here, it is shown that the FCS can also occur in flows such as Burgers vortex sheet. It is concluded that both canonical problems can be locally embedded in general shear flows and thus have widespread applicability.

Characteristic RNA foci of the abnormal hexanucleotide GGCCUG repeat expansion in spinocerebellar ataxia type 36 (Asidan)

BACKGROUND AND PURPOSE

Spinocerebellar ataxia type 36 (SCA36), also called Asidan, is an autosomal-dominant neurodegenerative disorder identified as a hexanucleotide GGCCTG repeat expansion in the first intron 1 of the NOP56 gene. In the present study, for the first time an autopsy sample from an Asidan patient was examined and cytoplasmic inclusions and (GGCCUG)n repeat RNA foci were detected.

METHODS

Hematoxylin and eosin staining, immunohistochemical staining, as well as fluorescence in situ hybridization were used to investigate the cytoplasmic inclusions of ubiquitin and p62 and the (GGCCUG)n repeat RNA foci.

RESULTS

The present study showed both ubiquitin- and p62-positive inclusions in the cytoplasm of the inferior olivary nucleus of the Asidan patient, (GGCCUG)n RNA foci in neuronal nuclei of the cerebrum, cerebellum, inferior olive, spinal cord and temporal muscle, and three types of RNA foci, i.e. single small, multiple small and giant. Of interest is that the giant RNA foci, nearly 10 μm in diameter, that were detected in Purkinje cells, spinal motor neurons and most frequently in the inferior olivary nucleus, may be responsible for pivotal clinical symptoms of Asidan.

CONCLUSIONS

The present study is the first report to show neuronal cytoplasmic inclusion bodies and giant RNA foci in an Asidan patient. The relationships between the giant RNA foci and neurodegeneration have yet to be studied.

Fully nonlinear mode competitions of nearly bicritical spiral or Taylor vortices in Taylor-Couette flow

Interactions between nearly bicritical modes in Taylor-Couette flow, which have been concerned with the framework of weakly nonlinear theory, are extended to fully nonlinear Navier-Stokes computation. For this purpose, a standard Newton solver for axially periodic flows is generalized to compute any mixed solutions having up to two phases, which typically arise from interactions of two spiral or Taylor vortex modes. Also, a simple theory is developed in order to classify the mixed solutions. With these methods, we elucidate pattern formation phenomena, which have been observed in a Taylor-Couette flow experiment. Focusing on the counter-rotating parameter range, all possible classes of interaction of various solutions with different azimuthal and axial wave numbers are considered within our computational restriction, and we observe numerous connection branches, e.g., footbridge solutions. Some of the mixed solutions result in a three-dimensional wavy spiral solution with axial relative periodicity or an axially doubly periodic toroidally closed vortex solution. The possible connection of the former solution family to spiral turbulence, which has been observed in highly counter-rotating Taylor-Couette flow, is discussed.

Superconductivity induced by longitudinal ferromagnetic fluctuations in UCoGe

From detailed angle-resolved NMR and Meissner measurements on a ferromagnetic (FM) superconductor UCoGe (T(Curie)∼2.5  K and T(SC)∼0.6  K), we show that superconductivity in UCoGe is tightly coupled with longitudinal FM spin fluctuations along the c axis. We found that magnetic fields along the c axis (H∥c) strongly suppress the FM fluctuations and that the superconductivity is observed in the limited magnetic-field region where the longitudinal FM spin fluctuations are active. These results, combined with model calculations, strongly suggest that the longitudinal FM spin fluctuations tuned by H∥c induce the unique spin-triplet superconductivity in UCoGe. This is the first clear example that FM fluctuations are intimately related with superconductivity.

A Study of Trap Profiles in Thin Silicon Dioxide Films at Dielectric Breakdown Using Percolation Model

A Monte Carlo simulation of wear-out process in thin silicon dioxide films is performed to investigate the correlation between the electron trap distribution and the dielectric breakdown. Non-uniformity of the trap generation and its dependence on the stress conditions are monitored by the measurements of the charge centroid. In order to include these experimental observations into Degraeve's percolation model [IEDM Tech. Dig., pp.863-866 (1995)], we introduce exponential trap profiles decaying from the Si/SiO2 interface. Our new model successfully reproduces critical threshold voltage shifts from the information about critical charge centroids for various stress conditions. Finally, as a reasonable explanation of the stress dependent breakdown properties, we suggest that the bond strain caused by lattice mismatch at the interface is accelerated by the electric field.

Traveling hairpin-shaped fluid vortices in plane Couette flow

Traveling-wave solutions are discovered in plane Couette flow. They are obtained when the so-called steady hairpin vortex state found recently by Gibson [J. Fluid Mech. 638, 243 (2009)] and Itano and Generalis [Phys. Rev. Lett. 102, 114501 (2009)] is continued to sliding Couette flow geometry between two concentric cylinders by using the radius ratio as a homotopy parameter. It turns out that in the plane Couette flow geometry two traveling waves having the phase velocities with opposite signs are associated with their appearance from the steady hairpin vortex state, where the amplitude of the phase velocities increases gradually from zero as the Reynolds number is increased. The solutions obviously inherit the streaky structure of the hairpin vortex state, but shape preserving flow patterns propagate in the streamwise direction. Other striking features of the solution are asymmetric mean flow profiles and strong quasistreamwise vortices which occupy the vicinity of only the top or bottom moving boundary, depending on the sign of the phase velocity. Furthermore, we find that the pitchfork bifurcation associated with the appearance of the solution becomes imperfect when the flow is perturbed by a Poiseuille flow component.

Anisotropic magnetic fluctuations in the ferromagnetic superconductor UCoGe studied by direction-dependent 59Co NMR measurements

We have carried out direction-dependent 59Co NMR experiments on a single crystal sample of the ferromagnetic superconductor UCoGe in order to study the magnetic properties in the normal state. The Knight-shift and nuclear spin-lattice relaxation rate measurements provide microscopic evidence that both static and dynamic susceptibilities are ferromagnetic with strong Ising anisotropy. We discuss that superconductivity induced by these magnetic fluctuations prefers spin-triplet pairing state.

Prediction of CCND1 amplification using plasma DNA as a prognostic marker in oesophageal squamous cell carcinoma

Background:

We aimed to develop a new biomarker to predict cyclin D1 (CCND1) status using plasma DNA in oesophageal squamous cell carcinoma (ESCC) patients.

Methods:

We evaluated the ratio of the CCND1 (11q13) dosage to the dopamine receptor D2 (DRD2; 11q22-23) dosage (C/D ratio) as CCND1 copy number. This study was divided into three steps: (1) Determination of a cutoff value for the C/D ratio in test scale; (2) Comparison of the C/D ratio in between plasma samples and cancer tissues in ESCC patients showing high plasma C/D ratio; (3) Validation study of the clinical application of the plasma C/D ratio as a diagnostic and prognostic marker, by comparing with clinicopathologic factors in 96 ESCC patients.

Results:

The plasma C/D ratio was significantly higher in the ESCC group than the controls (P=0.0134). A high plasma C/D ratio reflected the tumour C/D ratio, and significantly correlated with a poorer prognosis (P=0.0186). Moreover, the high C/D ratio was found to be an independent prognostic factor on multivariate analysis (P=0.0266; hazard ratio 5.988).

Conclusion:

Prediction of CCND1 amplification using plasma DNA is thought to be a promising prognostic biomarker in ESCC patients.

Induction of platelet derived-endothelial cell growth factor in the brain after ischemia

OBJECTIVES

Platelet derived-endothelial cell growth factor (PD-ECGF) is a highly potent angiogenic factor. Although angiogenesis plays an active role in pathophysiology of stroke, the expression pattern of this molecule in ischemic brain has not been investigated. In the present study, therefore, we investigated the change of PD-ECGF expression in the brain after ischemia.

METHODS

Using male Wistar rats, the right middle cerebral artery was occluded by a nylon thread for 90 minutes. The animals were decapitated 3 hours, 1, 4 and 10 days after the reperfusion, and frozen sections were prepared. We then performed immunohistochemistry for PD-ECGF and identified the cell phenotype which strongly expressed it by fluorescent double staining.

RESULTS

In the sham-operated brain, only small numbers of cells slightly expressed PD-ECGF. The number of positively stained cells increased at the peri-ischemic area from hour 3 of reperfusion. Not only small-sized cells but also large-sized cells became stained. The number of stained cells further increased, and peaked at day 4 for large-sized cells and at day 10 as to small-sized cells. Fluorescent double staining revealed that both large-sized and small-sized cells were neurons, indicating that neurons are the main source of PD-ECGF production in the ischemic brain.

DISCUSSION

PD-ECGF has a strong angiogenic property without vascular permeability increasing effect. This molecule may have a therapeutic potential for ischemic stroke treatment.

The validity of a hyperventilation test for an investigation of autonomic failure: assessment in patients with multiple system atrophy and Parkinson's disease

Although heart rate (HR) responses to hyperventilation (HV) have been used as a cardiovascular autonomic function test, autonomic involvement during HV remains uncertain. To clarify the relationship between autonomic activity and cardiovascular changes during HV, we compared cardiovascular responses during HV among subjects with different autonomic function, namely 16 patients with probable multiple system atrophy (MSA), 16 with possible MSA, 28 with Parkinson's disease (PD) and 28 healthy controls. Abnormalities of cardiovascular responses to head-up postural change and the Valsalva maneuver were definitely present in the order of probable MSA, possible MSA and PD, and abnormal HR and blood pressure (BP) responses during HV were observed in probable MSA and possible MSA, but not in PD. Unlike the significant difference in standard cardiovascular autonomic function tests, the HR and BP responses during HV were equivalent between probable and possible MSA. These findings suggest that cardiovascular control during HV may be affected not only by autonomic activity but also by other factors.

Neuroprotection and neurosupplementation in ischaemic brain

Possible strategies for treating ischaemic stroke include: (i) neuroprotection (preventing damaged neurons from undergoing apoptosis in the acute phase of cerebral ischaemia), and (ii) neurosupplementation (the repair of broken neuronal networks with newly born neurons in the chronic phase of cerebral ischaemia). In this paper, we review our recent progress in development of these distinct new strategies for treatment of damaged brain following a stroke. Firstly, we investigated the role of endogenous IL-6 (interleukin-6), which is one of the cytokines drastically induced by ischaemic stimuli, by administering IL-6RA (anti-IL-6 receptor monoclonal antibody) to mice. We found that endogenous IL-6 plays a critical role in neuroprotection and that its role may be mediated by STAT3 (signal transducer and activator of transcription-3) activation. Secondly, we studied the endogenous sources of the newly born neurons in the ischaemic striatum by region- and cell-type-specific cell labelling techniques. The results revealed that the SVZ (subventricular zone) is the principal source of the neuronal progenitors that migrate laterally towards the infarcted regions, and differentiate into newly born neurons. Finally, we developed a restorative stroke therapy with a bio-affinitive scaffold, which is an appropriate poly-porous structure releasing bioactive substances such as neurotrophic factor. This bio-affinitive scaffold is able to give an appropriate environment for newly born neurons. In future, we will combine these strategies to develop more effective therapies for treatment of strokes.

Competitive coexistence of superconductivity with antiferromagnetism in CeRhIn5

We carried out ac magnetic susceptibility measurements under pressures P on the heavy fermion antiferromagnet CeRhIn5. We report bulk superconductivity (SC) at ambient pressure with a transition temperature Tc approximately or equal to 90 mK. The degraded SC in a powdered or polished sample was restored by annealing, showing that the SC state is sensitive to inhomogeneity. In a coexistence region of the SC with antiferromagnetism (AF), we find that Tc(P)(n)TN(P)(1-n) = const where TN indicates a Néel temperature and n denotes a ratio of electronic specific heat coefficients below and above TN, indicating the competition of the SC and the AF for states at the Fermi surface.

Gap structure of the spin-triplet superconductor Sr2RuO4 determined from the field-orientation dependence of the specific heat

We report the field-orientation dependent specific heat of the spin-triplet superconductor Sr2RuO4 under the magnetic field aligned parallel to the RuO2 planes with high accuracy. Below about 0.3 K, striking fourfold oscillations of the density of states reflecting the superconducting gap structure have been resolved for the first time. We also obtained strong evidence of multiband superconductivity and concluded that the superconducting gap in the active band, responsible for the superconducting instability, is modulated with a minimum along the [100] direction.

Abnormal baroreceptor-mediated vasopressin release as possible marker in early diagnosis of multiple system atrophy

BACKGROUND

Although autonomic failure (AF) is a critical symptom of multiple system atrophy (MSA), it may not appear until late in the disease process.

OBJECTIVES

To clarify whether a detailed investigation of the autonomic nervous system in patients with MSA without overt AF demonstrates latent lesions of central cardiovascular control circuits and facilitates the early diagnosis of MSA.

METHODS

Autonomic function tests, and plasma noradrenaline (NA) and vasopressin (AVP) responses to head-up tilt (HUT), were studied in 12 patients with MSA with AF (probable MSA), 12 with MSA without overt AF (possible MSA), and 24 controls.

RESULTS

Abnormalities of cardiovascular autonomic function tests were prominent in the first group but mild in the second. Plasma NA and AVP increments upon HUT differed significantly among all three groups.

CONCLUSIONS

These results indicate that probable MSA involves diffuse degeneration of central cardiovascular control circuits. On the other hand, the discrepancies in possible MSA suggest a vulnerability of the noradrenergic (A1) neurones of the caudal ventrolateral medulla that are involved in AVP secretion. This finding also suggests that AVP increment may be useful as a diagnostic tool in the early stages of MSA.

Changes of middle latency somatosensory evoked potentials (SEPs) and alpha rythmicity associated with oculomotor processes

OBJECTIVES

To evaluate median nerve somatosensory evoked potentials (SEPs) and alpha waves during different eye conditions.

METHODS

Median SEPs and occipital electroencephalographs (EEG) were recorded in 6 eye conditions: eye-closed (EC), goggle (G), goggle+saccade (GS), saccade (S), eye-opened (EO) and pursuit (P), in 8 normal adults. Subjects saccaded their eyes reacting to auditory cues to watch a diode on the right or left side alternatively during the S condition, or imitated the same saccadic eye-movement as that in the S condition during the GS condition. In the P condition, subjects traced a small circle moving on a computer screen.

RESULTS

Compared with the EC and G conditions, N30 (P25-N30 or P14-N30) amplitudes in C4' were significantly larger and the mean amplitude and power of the alpha band was significantly attenuated in the other 4 conditions. The amplitude and power of the alpha band differed significantly between the GS and S conditions, whereas N30 amplitudes were similar between the two conditions. N30-P45 or P45-N60 amplitudes in C4' were significantly larger in the P condition than in other conditions.

CONCLUSIONS

Present findings suggest that different neural mechanisms cause alpha blocking and the modification of middle latency SEPs associated with oculomotor control.

Serial MRI findings in patient with chronic cryptococcus meningo-encephalitis

We describe the serial changes of magnetic resonance imaging (MRI) in a patient with chronic cryptococcus meningo-encephalitis. In the subacute phase, MRI revealed a focal lesion with hyperintensity on T2-weighted image (WI) in the left thalamus. At 11 months after the onset, MRI showed a focal lesion with hyperintensity on T2-WI in the right pons that was enhanced with gadolinium (Gd). At 13 months after the onset, the lesion in the left thalamus became rim enhanced with Gd. After antifungal therapy (amphotericin B and 5-flucytosine), the rim enhancement in the left thalamus and the high signal intensity area in the right pons decreased. Cryptococcoma should be in the differential from other ring enhancing lesions.

Substance P immunoreactivity in the enteric nervous system in Rett syndrome

Rett syndrome is associated with profound mental retardation and motor disability in girls. It has a characteristic clinical phenotype which includes abnormalities of the autonomic nervous system. Feeding impairment and severe constipation are two symptoms of this autonomic dysfunction. Substance P, an important peptide in the autonomic nervous system, is decreased in the cerebrospinal fluid of Rett syndrome. We have demonstrated that substance P immunoreactivity is significantly decreased in Rett syndrome brain-stem and may be related to the autonomic dysfunction. In this study, we have continued the investigation of substance P in the enteric nervous system. We immunohistochemically examined the normal developing bowel in 22 controls (ages, 14 gestational weeks to 31 years) using formalin fixed tissue, with antibodies to substance P, tyrosine hydroxylase and vasoactive intestinal peptide. We compared the immunoreactivity of normal controls with 14 cases of Rett syndrome (ages, 5-41 years) and observed that the expression of substance P, tyrosine hydroxylase and vasoactive intestinal peptide immunoreactivity in the bowel in Rett syndrome was not significantly different from that of controls. This suggests that the feeding impairment and constipation in Rett syndrome relate to dysfunction of the autonomic nervous system originating outside of the bowel, in the brain-stem, as suggested by our previous study.

Impaired novelty P3 potentials in multiple system atrophy--correlation with orthostatic hypotension

Although neuropsychological tests demonstrate frontal lobe dysfunction in multiple system atrophy (MSA), assessment of frontal function using event-related brain potentials (ERPs) has not been sufficiently performed in MSA. The correlation between frontal lobe dysfunction and orthostatic hypotension (OH), which is known to cause frontal hypoperfusion, remains unclear. Our objectives were to assess frontal lobe dysfunction in MSA patients using ERPs and to elucidate the relevance of OH to changes in ERPs. Nine consecutive patients with MSA and nine age- and gender-matched healthy controls were compared by performance in the Wisconsin Card Sorting Test (WCST) and somatosensory ERPs to target and novel stimuli, namely, parietal maximal P3 (target P3) and fronto-central P3 (novelty P3), respectively. The correlation between novelty P3 and OH was evaluated in the MSA group. The MSA group showed a poorer performance in categories achieved (CA), total errors (TE) and perseverative errors by Nelson's (PEN) method in the WCST compared with the control group (CA and PEN: p<0.01; TE: p<0.02). Novelty and target P3s in the MSA group showed significantly prolonged latency (novelty: p<0.05; target: p<0.01) and reduced amplitude (novelty: p<0.02; target: p<0.01) compared with the control group. There was a significant negative correlation between novelty P3 latency and a drop in systolic blood pressure (r=0.76; p<0.02). Abnormalities of novelty P3 in the MSA group might reflect frontal lobe dysfunction, namely failure of attentional set-shifting, that was identified by the WCST. OH may play a role in the development of frontal lobe dysfunction in MSA.

Hippocampus in relation to mental sweating response evoked by memory recall and mental calculation: a human electroencephalography study with dipole tracing

Mental-sweating response (MSR) was observed in the palm when the subject was asked to perform a mentally stressful task such as memory recall or mental calculation. About 4 s before the development of MSR, small MSR-related wavelets (MSR wavelets) and large waves were randomly generated on electroencephalograph. After differentiating the two types of waves, we calculated locations of the current dipole of MSR wavelets using the two-dipole model of the SSB/dipole tracing method. The result showed that one current dipole of MSR wavelets was consistently located in the hippocampus while the other dipole was widely dispersed in the cortex during memory recall and mental calculation.

Postmenopausal changes in production of type 1 and type 2 cytokines and the effects of hormone replacement therapy

OBJECTIVE

An appropriate defense against infective agents or malignant cells is attributed to the exquisitely balanced T helper 1 type (cellular) and T helper 2 type (humoral) immune reactions. We investigated the effect of hormone replacement therapy (HRT) on postmenopausal changes in the production of interferon (IFN)-gamma and interleukin (IL)-10, a type 1 and a type 2 cytokine, respectively.

DESIGN

Both cytokines were measured by ELISA in the supernatant of lipopolysaccharide-stimulated whole blood cells from 72 untreated and 44 HRT-treated women. Thirteen women were examined before and during HRT.

RESULTS

The production of IFN-gamma in women in their 40s and in postmenopausal women was significantly higher compared with that of younger women. However, IFN-gamma fell to the lowest level in the late postmenopausal stage, whereas the production of IL-10 increased gradually with age and in parallel with the postmenopausal period. Thus, in women in the mid-and late postmenopausal period, excessive production of type 2 cytokine (IL-10) compared with type 1 cytokine (IFN-gamma) occurred. The IFN-gamma levels of women on HRT were significantly lower than those of untreated women in the early and mid-postmenopausal stages, and IL-10 levels of women on HRT were significantly lower than those of untreated women in the mid-and late postmenopausal stages. HRT induced a significant decrease in the production of IL-10 and tended to lower the level of IFN-gamma.

CONCLUSIONS

Production of IL-10 is augmented in postmenopausal women. HRT probably prevents postmenopausal women from an aberration of the immune system by improving the balance of type 1 and type 2 immune reactions.

Observations on recurrent syncope and presyncope in 641 patients

BACKGROUND

Syncope is a common disorder that is potentially disabling and affects both young and old. Once neurological, cardiological, and metabolic causes have been excluded, there remains a group in which diagnosis is unclear; some may have an autonomic basis. We therefore did a retrospective study on consecutive patients referred to our tertiary referral autonomic centres between 1992 and 1998 with recurrent syncope and presyncope, in whom non-autonomic causes, before referral, had been sought and excluded. The object was to find out whether autonomic investigation helped diagnosis.

METHODS

Data from case notes and from the autonomic database on 641 patients were analysed. Syncopal patients with a known or provisional diagnosis of autonomic failure were excluded from analysis. The role of screening tests in establishing or excluding an autonomic cause was assessed. Response to additional autonomic tests (such as head-up tilt with or without venepuncture, and food challenge and exercise) was documented. Some patients underwent further testing if non-autonomic neurological, psychiatric, and other disorders were considered.

FINDINGS

Screening autonomic function tests indicated orthostatic hypotension and confirmed chronic autonomic failure in 31 (4.8%) patients. Neurally mediated syncope was diagnosed in 279 (43.5%) on the basis of clinical features and autonomic testing. Most had vasovagal syncope (227 [35%]); other causes included carotid sinus hypersensitivity (37 [5.8%]), and a group of 15 (2.3%) were associated with rarer causes such as micturition and swallowing. Miscellaneous cardiovascular causes (systemic hypotension, arrhythmias), or drugs, contributed to syncope in 53 (8.3%). Non-autonomic neurological causes included vestibular dysfunction (32 [5%]) and epilepsy (11 [1.7%]). In 56 (8.7%) a psychiatric cause was thought to be contributory. In 179 (27.9%), syncope was of unknown cause.

INTERPRETATION

In recurrent syncope and presyncope, when cardiac, neurological, and metabolic causes have been excluded, autonomic investigation can aid management by making, confirming, or excluding various factors or diagnoses.

B cell subsets in postmenopausal women and the effect of hormone replacement therapy

OBJECTIVES

In elderly subjects the capacity for antibody production is depressed. This immunosenescence state of humoral immunity is associated with the occurrence of autoimmune disorders involving CD5+ B (B-1) cells. Since estrogen is capable of stimulating the production of autoantibodies, this sex steroid hormone may be a contributing cause of the higher incidence of autoimmune diseases in women. In the present study, B cell subsets in women during the postmenopausal period was determined. The effect of hormone replacement therapy (HRT) on B cell subsets was examined to establish whether the administration of gonadal hormones influence humoral immunity in postmenopausal women.

METHODS

Forty six untreated pre- and postmenopausal women and 39 women on HRT were studied. The proportion of B-1 (CD5+) and conventional CD5- B (B-2) lymphocytes was determined by two-color flow cytometry. Serum autoantibodies to a nuclear antigen and to interleukin (IL)-1alpha were measured by immunofluorescence and by radioimmunoassay, respectively. Thirteen women were examined prospectively before and during HRT.

RESULTS

In late postmenopausal women (> or = 30 years postmenopausal period), the proportion of B-2 cells was significantly reduced (p<0.01) compared to those of premenopausal and perimenopausal women. HRT induced a significant (p<0.01) increase in the percentage of B-2 cells, while that of B-1 cells remained unchanged. HRT did not affect autoantibody production.

CONCLUSION

HRT may retard the progress of immunosenescence by increasing the production of B-2 cells. Moreover, HRT appears not to increase the risk of autoimmune diseases developing in postmenopausal women.