Effective light cone and digital quantum simulation of interacting bosons

The speed limit of information propagation is one of the most fundamental features in non-equilibrium physics. The region of information propagation by finite-time dynamics is approximately restricted inside the effective light cone that is formulated by the Lieb-Robinson bound. To date, extensive studies have been conducted to identify the shape of effective light cones in most experimentally relevant many-body systems. However, the Lieb-Robinson bound in the interacting boson systems, one of the most ubiquitous quantum systems in nature, has remained a critical open problem for a long time. This study reveals a tight effective light cone to limit the information propagation in interacting bosons, where the shape of the effective light cone depends on the spatial dimension. To achieve it, we prove that the speed for bosons to clump together is finite, which in turn leads to the error guarantee of the boson number truncation at each site. Furthermore, we applied the method to provide a provably efficient algorithm for simulating the interacting boson systems. The results of this study settle the notoriously challenging problem and provide the foundation for elucidating the complexity of many-body boson systems.

Pioglitazone-incorporated microspheres alleviates cardiac dysfunction through macrophage polarization in a rat myocardial infarction model

 

Inflammatory processes are essential for the repair processes after myocardial infarction. Among inflammatory cells involved in this process, macrophages play a critical role through polarization in pro-inflammatory M1 or reparative M2 subtype. Pioglitazone, known as a treatment drug for diabetes mellitus, is reported to regulate macrophage polarization toward reparative M2 subtype. Poly L-lactic-co-glycolic acid (PLGA) has been widely accepted as the delivery carrier in drug delivery system (DDS).

Here, we aimed to validate the therapeutic effects and investigate the mechanisms of DDS-based treatment using pioglitazone to left ventricular remodeling after myocardial infarction.

Pioglitazone-incorporated PLGA microspheres (PGZ-MS) were prepared and the drug release profile was evaluated. The concentration of interleukin-10 secreted from murine bone marrow derived macrophages incubated with PGZ-MS was quantified in the culture supernatant. To validate the therapeutic potential of PGZ-MS in vivo, Sprague-Dawley rats were subjected to permanent left coronary artery ligation to induce myocardial infarction. Mock-MS (100 μg) or PGZ-MS (100 μg) was injected to the infarct region just after induction (n=9–11/group). Cardiac function and left ventricular size were assessed by echocardiography. At 28-day after surgery, rats were sacrificed, and excised hearts were evaluated histologically.

PGZ-MS released 1.8±0.3% of incorporated PGZ within 24 hours and 29.5±1.2% within 14 days indicating sustained release of PGZ in vitro. PGZ-MS augmented Interleukin-10 release from bone marrow derived macrophages, indicating polarization toward reparative M2 subtype. PGZ-MS significantly ameliorated cardiac function after myocardial infarction (fractional shortening: MI vs MI+Mock-MS vs MI+PGZ-MS, 24.4±1.1 vs 24.3±1.6 vs 32.2±1.4%; P=0.0035) with reverse remodeling (wall thickness: MI vs MI+Mock-MS vs MI+PGZ-MS, 0.69±0.12 vs 0.71±0.13 vs 1.06±0.09; P=0.03). Immunohistochemical analyses revealed that PGZ-MS enhanced macrophage polarization toward reparative M2 subtype (ratio of reparative M2 macrophages: 0.39±0.03 vs 0.42±0.02 vs 0.54±0.02; P=0.0004) and attenuated apoptosis of cardiomyocytes in the ischemic border zone (MI vs MI+Mock-MS vs MI+PGZ-MS, 2.6±0.2 vs 1.9±0.2 vs 1.2±0.2 cells/field; P=0.002).

In the present study, we confirmed that PGZ-MS could realize sustained release of pioglitazone which resulted in sustained effect of macrophage polarization and attenuated left ventricular remodeling accompanied with the amelioration of cardiac dysfunction and cardiomyocytes apoptosis. The strategy of DDS-based macrophage polarization might serve as a promising strategy in cardiac regenerative therapy for ischemic heart disease in the future.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Grants-in-Aid for Scientific Research from the Ministry of Education, Science, Sports and Culture of Japan

Fate of Measurement-Induced Phase Transition in Long-Range Interactions

We consider quantum many-body dynamics under quantum measurements, where the measurement-induced phase transitions (MIPs) occur when changing the frequency of the measurement. In this work, we consider the robustness of the MIP for long-range interaction that decays as r^{-α} with distance r. The effects of long-range interactions are classified into two regimes: (i) the MIP is observed (α>α_{c}), and (ii) the MIP is absent even for arbitrarily strong measurements (α<α_{c}). Using fermion models, we demonstrate both regimes in integrable and nonintegrable cases. We identify the underlying mechanism and propose sufficient conditions to observe the MIP, that is, α>d/2+1 for general bilinear systems and α>d+1 for general nonintegrable systems (d: spatial dimension). Numerical calculation indicates that these conditions are optimal.

Lieb-Robinson Bound and Almost-Linear Light Cone in Interacting Boson Systems

In this work, we investigate how quickly local perturbations propagate in interacting boson systems with Bose-Hubbard-type Hamiltonians. In general, these systems have unbounded local energies, and arbitrarily fast information propagation may occur. We focus on a specific but experimentally natural situation in which the number of bosons at any one site in the unperturbed initial state is approximately limited. We rigorously prove the existence of an almost-linear information-propagation light cone, thus establishing a Lieb-Robinson bound: the wave front grows at most as t log^{2}(t). We prove the clustering theorem for gapped ground states and study the time complexity of classically simulating one-dimensional quench dynamics, a topic of great practical interest.

Absence of Fast Scrambling in Thermodynamically Stable Long-Range Interacting Systems

In this study, we investigate out-of-time-order correlators (OTOCs) in systems with power-law decaying interactions such as R^{-α}, where R is the distance. In such systems, the fast scrambling of quantum information or the exponential growth of information propagation can potentially occur according to the decay rate α. In this regard, a crucial open challenge is to identify the optimal condition for α such that fast scrambling cannot occur. In this study, we disprove fast scrambling in generic long-range interacting systems with α>D (D: spatial dimension), where the total energy is extensive in terms of system size and the thermodynamic limit is well defined. We rigorously demonstrate that the OTOC shows a polynomial growth over time as long as α>D and the necessary scrambling time over a distance R is larger than t≳R^{[(2α-2D)/(2α-D+1)]}.

Clustering of Conditional Mutual Information for Quantum Gibbs States above a Threshold Temperature

We prove that the quantum Gibbs states of spin systems above a certain threshold temperature are approximate quantum Markov networks, meaning that the conditional mutual information decays rapidly with distance. We demonstrate the exponential decay for short-ranged interacting systems and power-law decay for long-ranged interacting systems. Consequently, we establish the efficiency of quantum Gibbs sampling algorithms, a strong version of the area law, the quasilocality of effective Hamiltonians on subsystems, a clustering theorem for mutual information, and a polynomial-time algorithm for classical Gibbs state simulations.

Eigenstate Thermalization from the Clustering Property of Correlation

The clustering property of an equilibrium bipartite correlation is one of the most general thermodynamic properties in noncritical many-body quantum systems. Herein, we consider the thermalization properties of a system class exhibiting the clustering property. We investigate two regimes, namely, regimes of high and low density of states corresponding to high- and low-energy regimes, respectively. We show that the clustering property is connected to several properties on the eigenstate thermalization through the density of states. Remarkably, the eigenstate thermalization is obtained in the low-energy regime with a sparse density of states, which is typically seen in gapped systems. For the high-energy regime, we demonstrate the ensemble equivalence between microcanonical and canonical ensembles even for a subexponentially small energy shell with respect to the system size, which eventually leads to the weak version of eigenstate thermalization.

Heating in Integrable Time-Periodic Systems

We investigate a heating phenomenon in periodically driven integrable systems that can be mapped to free-fermion models. We find that heating to the high-temperature state, which is a typical scenario in nonintegrable systems, can also appear in integrable time-periodic systems; the amount of energy absorption rises drastically near a frequency threshold where the Floquet-Magnus expansion diverges. As the driving period increases, we also observe that the effective temperatures of the generalized Gibbs ensemble for conserved quantities go to infinity. By the use of the scaling analysis, we reveal that, in the limit of infinite system size and driving period, the steady state after a long time is equivalent to the infinite-temperature state. We obtain the asymptotic behavior L^{-1} and T^{-2} as to how the steady state approaches the infinite-temperature state as the system size L and the driving period T increase.

Rigorous Bound on Energy Absorption and Generic Relaxation in Periodically Driven Quantum Systems

We discuss the universal nature of relaxation in isolated many-body quantum systems subjected to global and strong periodic driving. Our rigorous Floquet analysis shows that the energy of the system remains almost constant up to an exponentially long time in frequency for arbitrary initial states and that an effective Hamiltonian obtained by a truncation of the Floquet-Magnus expansion is a quasiconserved quantity in a long time scale. These two general properties lead to an intriguing classification on the initial stage of relaxation, one of which is similar to the prethermalization phenomenon in nearly integrable systems.

Prevalence of Parkinson's disease and atypical parkinsonian syndromes in a rural Japanese district

OBJECTIVES

To investigate the prevalence of Parkinson's disease (PD) and atypical parkinsonian syndromes (APS) in a rural Japanese district.

METHOD

Collaboration with the medical institutions, the long-term care insurance system facilities, and the public health office.

RESULTS

The crude prevalence rates were 175 per 100,000 (95% CI: 143-206) for PD, 18 (8-28) for progressive supranuclear palsy, 17 (7-26) for multiple system atrophy (MSA), and 9 (2-16) for corticobasal degeneration. The age-adjusted prevalence rates were 109 per 100,000 (88-134), 10 (2-17), 13 (4-21), and 6 (0-12), for each condition. There was a preponderance of women with PD and of men with APS. Nine of the 116 PD patients and 7 of the 29 APS patients were newly diagnosed in this study.

CONCLUSIONS

There are high prevalence rates for PD and APS and suboptimal recognition of APS. This is the first epidemiological prevalence study of MSA from Japan.

Lateral Grain Growth in the Excimer Laser Crystallization of Poly-Si

We have succeeded in obtaining nondoped, thin poly-Si film (thickness ∼500Å) with excellent crystallinity and large grain size (Maximum grain size ∼4.5 μ m) by an excimer laser annealing Method, which offers the features of low-temperature processing and a short processing time. The grain size distribution shrinks in the region around 1.5 μ m and this poly-Si film exhibits a strong (111) crystallographic orientation. Poly-Si thin film transistors using these films show quite a high field effect mobility of 440cm2/V · s below 600°C process.

Blockade of Th1 chemokine receptors ameliorates pulmonary granulomatosis in mice

Sarcoidosis is a granulomatous disease of unknown aetiology. We identified immunological targets for the treatment of pulmonary granulomatosis using a murine model generated with Propionibacterium acnes. Sensitisation and challenge using heat-killed P. acnes and dendritic cells (DCs) were performed to produce pulmonary granulomatosis in C57BL/6 mice. Immunological analyses using ELISA as well as cDNA microarray analysis were used to search for cytokines or chemokines associated with the formation of granulomas in the lungs. Co-administration of P. acnes and DCs reproducibly induced the formation of pulmonary granulomas, which resembled sarcoid granulomas. The cDNA microarray assay demonstrated that the gene expression of CXCL9 and CXCL10, ligands for CXCR3, and of CCL4, a ligand for CCR5, was strongly upregulated during granulomatosis. ELISA confirmed that levels of CXCL9 and CXCL10 as well as T-helper (Th)1 cytokines and chemokines including tumour necrosis factor-α and interferon-γ were elevated in bronchoalveolar lavage fluid (BALF). The blockade of Th1 chemokine receptors using TAK-779, a dual blocker for CXCR3 and CCR5, led to reduced numbers of CXCR3+CD4+ and CCR5+CD4+ T-cells in BALF. Furthermore, administration of TAK-779 ameliorated the granulomatosis. The targeted inhibition of Th1 chemokines might be useful for inhibiting Th1-biased granulomatous diseases, including sarcoidosis.

[Myers technique and patch enlargement of ascending aorta for diffuse supravalvular aortic stenosis]

A 6-year-old boy was diagnosed with aggravation of diffuse supravalvular aortic stenosis (SVAS). The pressure gradient between the sinus of Valsalva and ascending aorta was 48 mmHg. The diameter of the sino-tubular junction was 7 mm and the ascending aorta was hypoplastic. We performed Myers operation because 3 sinus reconstructions had resulted in superior hemodynamics and reductions in both mortality rate and need for reoperation. We avoided using autologous pericardium because of the possibility of shrinkage and aneurysm. We could easily perform patch enlargement of the ascending aorta by selective cerebral perfusion. The postoperative course was excellent and there was no SVAS or aortic regurgitation (AR). A catheterization showed the pressure gradient was 5 mmHg with trivial AR upon follow-up at 1 year.

[Stenosis of left coronary artery ostium by a hypoplastic cusp]

Occlusion of a coronary ostium due to fusion of the aortic cusp to the aortic wall is a rare but noteworthy anomaly, because it may cause a sudden death. We report a 9-year-old girl with severe stenosis of the left coronary ostium by the aortic cusp that fused to the aortic wall. The left coronary flow was restored by excision of the adherent left aortic cusp, and aortic valve replacement was performed with the technique of bilateral enlargement of the aortic valve ring (Yamaguchi's method) to prevent prosthesis-patient mismatch in the future. The patient had an uneventful recovery and was discharged 14th postoperative day (POD). Postoperative angiography showed no coronary ostial stenosis.

Flow regime classification in air-magnetic fluid two-phase flow

A new experimental/numerical technique of classification of flow regimes (flow patterns) in air-magnetic fluid two-phase flow is proposed in the present paper. The proposed technique utilizes the electromagnetic induction to obtain time-series signals of the electromotive force, allowing us to make a non-contact measurement. Firstly, an experiment is carried out to obtain the time-series signals in a vertical upward air-magnetic fluid two-phase flow. The signals obtained are first treated using two kinds of wavelet transforms. The data sets treated are then used as input vectors for an artificial neural network (ANN) with supervised training. In the present study, flow regimes are classified into bubbly, slug, churn and annular flows, which are generally the main flow regimes. To validate the flow regimes, a visualization experiment is also performed with a glycerin solution that has roughly the same physical properties, i.e., kinetic viscosity and surface tension, as a magnetic fluid used in the present study. The flow regimes from the visualization are used as targets in an ANN and also used in the estimation of the accuracy of the present method. As a result, ANNs using radial basis functions are shown to be the most appropriate for the present classification of flow regimes, leading to small classification errors.

RNA polymerase β-subunit gene (rpoB) sequence analysis for the identification of Bacteroides spp

Partial rpoB sequences (317 bp) of 11 species of Bacteroides, two Porphyromonas spp. and two Prevotella spp. were compared to delineate the genetic relationships among Bacteroides and closely related anaerobic species. The high level of inter-species sequence dissimilarities (7.6-20.8%) allowed the various Bacteroides spp. to be distinguished. The position of the Bacteroides distasonis and Bacteriodes merdae cluster in the rpoB tree was different from the position in the 16S rRNA gene tree. Based on rpoB sequence similarity and clustering in the rpoB tree, it was possible to correctly re-identify 80 clinical isolates of Bacteroides. In addition to two subgroups, cfiA-negative (division I) and cfiA-positive (division II), of Bacteroides fragilis isolates, two distinct subgroups were also found among Bacteroides ovatus and Bacteroides thetaiotaomicron isolates. Bacteroides genus-specific rpoB PCR and B. fragilis species-specific rpoB PCR allowed Bacteroides spp. to be differentiated from Porphyromonas and Prevotella spp., and also allowed B. fragilis to be differentiated from other non-fragilisBacteroides spp. included in the present study.

[Primary biventricular repair for interrupted aortic arch with left ventricular outflow tract obstruction and tricuspid valve regurgitation; report of a case]

An interrupted aortic arch was diagnosed in a 10-day-old girl weighing 3.3 kg, as was perimembranous ventricular septal defect (VSD) and severe tricuspid valve regurgitation (TR). The subaortic diameter was 3.6 mm and the aortic valve (3.7 mm in diameter) was bicuspid. We chose definitive repair, modified Yasui procedure, because of severe TR and no straddling of mitral valve. In primary biventricular repair, we undertook extended aortic arch anastomosis. Left ventricular outflow tract reconstruction consisted of intracardiac rerouting from the VSD to the pulmonary artery by using expanded-polytetrafluoroethylene (ePTFE) and Damus-Kaye-Stansel (DKS) anastomosis. Right ventricular outflow tract reconstruction was performed by the Rastelli procedure with an ePTFE valved conduit. Moreover, we carried out semicircular annuloplasty for severe TR.

Effect of skin temperature on the ion reabsorption capacity of sweat glands during exercise in humans

The effect of skin temperature on the ion reabsorption capacity of sweat glands during exercise in humans is unknown. In this study, eight healthy subjects performed a 60-min cycling exercise at a constant intensity (60% VO(2max)) under moderate (25 degrees C) and cool (15 degrees C) ambient temperatures at a constant relative humidity of 40%. The sweating rate (SR), index of sweat ion concentration (ISIC) by using sweat conductivity, esophageal temperature (Tes), mean skin temperature, and heart rate (HR) were measured continuously under both ambient temperatures. The SR and ISIC were significantly lower at the cool ambient temperature versus the moderate temperature. There were no significant differences in the changes in HR and esophageal temperature between these ambient temperature conditions, while the mean skin temperature was significantly lower at the cool ambient temperature by almost 3 degrees C (P < 0.05). The slopes of the relationships between Tes and the SR and ISIC were significantly lower and the thresholds of these relationships were significantly higher at the cool ambient temperature (P < 0.05). The ion reabsorption capacity of the sweat glands was significantly lower (P < 0.05) in a cool environment (0.21 +/- 0.04 vs. 0.52 +/- 0.06 mg/cm(2)/min at 15 and 25 degrees C, respectively) as evaluated using the relationships for SR and ISIC. The results suggest that the ion reabsorption capacity of the sweat glands is influenced by skin temperature during exercise in humans.

Changes in the index of sweat ion concentration with increasing sweat during passive heat stress in humans

To investigate the pattern changes in the index of sweat ion concentration at skin surface with increasing sweat during passive heat stress in humans, we measured conductivity of the perfused water with sweat as the index of sweat ion concentration and sweat rate, continuously at the chest skin surface. Eight healthy subjects (22.4 +/-1.0 years) were passively heated by lower-leg immersion in a hot water bath of 42 degrees C for 50 min in an ambient temperature of 28 degrees C and relative humidity of 50%. The internal temperature (Tor) thresholds of sweat rate and index of sweat ion concentration were almost similar. Concomitant onset for the index of sweat ion concentration and sweat rate occurred but two types of linear regression lines were identified in the relationship between the index of sweat ion concentration and sweat rate at a boundary sweat rate value of 0.30 +/- 0.08 mg cm(-2) min(-1). The slope of the regression line at low levels of sweat (slope 0.02 +/- 0.01 V mg(-1) cm(-2) min(-1)) was significantly gradual compared with that at moderate levels of sweat (slope 0.30 +/- 0.08 V mg(-1) cm(-2) min(-1)) (P<0.05). These results suggest that at low levels of sweat the index of sweat ion concentration responds gradually with respect to sweat rate, which may be due to the ion reabsorption capacity of the sweat duct, and then the index of sweat ion concentration increased steeply with sweat rate.

[Sandwich technique for closing of the large muscular Swiss-cheese type ventricular septal defects]

A 9-year-old girl, who has had a diagnosis as a Taussig-Bing anomary, underwent an original Jatene procedure (o-J) 2 months after birth. This time, she had a diagnosis of the muscular multiple ventricular septal defects (mVSD) and pulmonary stenosis after o-J. The mVSD was Swiss-cheese type and was large from the proximal of the infundibular septum to the apex and posterior of the septum. It was closed by the sandwich technique using a pair of felt patches, which of one was placed at right ventricular side and the other was at left ventricular side, slightly larger than the whole area of the mVSD. The patch fixation was placed with 1 stitch at the center between the patches and a few stitches around the right ventricular side patch to the ventricular septum. Postoperative cardiac function was uneventful regardless of the very large patches placed at the ventricular septum and the cardiac catheterization after 1 year postoperatively showed the pulmonary/systemic blood flow ratio was 1.0. This technique for the closure of the large Swiss-cheese type mVSD can be considered to be very effective.

Pulmonary angiomyolipoma recurring 26 years after nephrectomy for angiomyolipoma: benign clinical course

Angiomyolipoma (AML), a benign renal tumor, has various clinical forms, and the nature of AML is not sufficiently understood because of few reports of long-term observation. We report a 57-year-old female without tuberous sclerosis who developed multiple pulmonary AML 26 years after a right nephrectomy for renal AML. A computed tomogram demonstrated multifocal round lesions with lipid-like density throughout both lung fields. An open lung biopsy revealed a histological diagnosis of pulmonary AML. An abdominal computed tomogram was also compatible with splenic AML. She has been in good health for 12 years since the lung biopsy over the 38 years since the nephrectomy. This case suggests that multicentric AML can recur at distant organs even after long-term silence in a patient who has a past history of renal AML.

Inhibitory effects of Centella asiatica on azoxymethane-induced aberrant crypt focus formation and carcinogenesis in the intestines of F344 rats

Effects of the water extract of Centella asiatica Linn. on formation of azoxymethane (AOM)-induced aberrant crypt foci (ACF) and intestinal tumorigenesis in male F344 rats were investigated. Treatment with the extract significantly decreased the number of larger ACF (with four or more crypts per focus) in the large intestine in the early stage, while the number of methylated DNA adducts was not decreased compared with that in the AOM-treated group. In the post-initiation stage, the extract significantly decreased the total number of ACF and the number of larger ACF, accompanied by a decrease in the 5-bromo-2'-deoxyuridine-labeling index and an increase in the induction of apoptotic cells in the colonic mucosa. The incidences of neoplasms, the numbers of adenocarcinomas in the small intestines and entire intestines, and sizes of neoplasms in the entire intestines in rats fed C. asiatica extract at a dose of 10 mg/kg were smaller than those in rats given AOM alone (p < 0.05). The extract at a dose of 100 mg/kg significantly reduced the multiplicity of neoplasms in the small intestine (p < 0.05). These results suggest that inhibition of the formation of AOM-induced ACF by C. asiatica extract is associated with modification of cell proliferation and induction of apoptosis in colonic crypts and that the extract has a chemopreventive effect on colon tumorigenesis.

[Successful staged repair of a symptomatic neonate of tetralogy of Fallot with severe absent pulmonary valve syndrome]

Tetralogy of Fallot with absent pulmonary valve has been classified to a few groups. The most severe one is characterized by symptomatic onset immediately after birth. The others are no or slightly symptomatic at least during their neonatal period. In a severely symptomatic 12-day-old neonate of tetralogy of Fallot with absent pulmonary valve who had required intubation immediately after birth, tight pulmonary banding and left side modified Blalock-Taussig shunt were performed on emergency basis. Consequently, prior massive pulmonary regurgitation was decreased significantly. Forty-five days after this first stage operation, he weaned from respiratory management. At 1-year-old, radical repair based on conotruncal repair, which consisted of patch closure of ventricular septal defect preserving the tricuspid septal leaflet function, resection of anterior wall of enlarged left pulmonary artery, and right ventricular outflow tract reconstruction using autologous tissue and a pericardial patch was performed. Bicuspid pulmonary valve, posterior one of procured autologous pulmonary wall and anterior one of polytetrafluoroethylene (PTFE) respectively, was created to minimize deterioration of the pulmonary insufficiency. Although postoperative cardiac function was kept feasible showing his central venous pressure of 7 mmHg in the main, postoperative general course was eventful especially regarding the respiratory function. The patient was weaned from the prolonged ventilator management 5 months after this radical repair eventually. Generally, to diminish the massive pulmonary regurgitation in early lifetime period could reduce a progressive airway obstruction and minimize pulmonary tissue damage. However, even after the total correction in this case, considerable peripheral segmental pulmonary obstructive lesions were persistent according to the perfusion lung scanning with 99mTc macroaggregated albumin and 99mTechnegas ventilation lung scanning studies. This persistent, supposed to be innate, pulmonary obstructive lesions might prevent ordinal recovery after cardiac radical repair for this most severe subtype of absent pulmonary valve syndrome.

[Valvuloplasty for mitral regurgitation immediately following Kawasaki disease without abnormal coronary arteries lesion; report of a case]

It is not uncommon that valve disease is complicated with Kawasaki disease (KD). However, it is rare to show normal coronary arteries simultaneously. We experienced a case of valvuloplasty towards the mitral regurgitation (MR) followed immediately after KD showing normal coronary arteries. A 3 year-old-female, with a diagnosis of KD at 4 months after birth, was referred to our hospital 5 months after birth. The echocardiography detected a moderate MR. The preoperative catheterization at 2.5 years old showed grade III MR, enlargement of left atrium and left ventricle, pulmonary capillary wedge pressure (PCWP) = 12 mmHg, left ventricular ejection fraction (LVEF) = 675, and normal coronary arteries. Pulmonary hypertention was not revealed. The operative findings showed mitral valve prolapse due to the elongation of the chordae of the anterior leaflet. She underwent artificial chordal reconstruction using expanded polytetrafluoroethylene sutures and mitral annuloplasty by Kay-Reed method. The postoperative course was uneventful, and she was discharged on postoperative day 19.

Betulinic acid augments the inhibitory effects of vincristine on growth and lung metastasis of B16F10 melanoma cells in mice

We examined the antitumour effect of a combination of betulinic acid (BA) and vincristine (VCR) on murine melanoma B16F10 cells in vitro and in vivo. Betulinic acid, a pentacyclic triterpene, showed a synergistic cytotoxic effect on melanoma cells by combinational use of VCR. Betulinic acid and VCR induced cell cycle arrest at different points (BA at G1 phase and VCR at G2/M phase) and caused apoptosis in B16F10 melanoma cells. In the in vivo study, VCR inhibited metastasis of tumour cells to the lung. The addition of BA to VCR augmented suppression of the experimental lung metastasis of melanoma cells in C57BL/6 mice. The number of lung nodules of more than 1 mm in diameter in mice treated with BA and VCR was less than that in mice treated with VCR alone. These results suggest that BA is an effective supplement for enhancing the chemotherapeutic effect on malignant melanoma.

Augmenting effect of acetic acid for acidification on bactericidal activity of hypochlorite solution

AIMS

Bactericidal activity of chlorine solution is enhanced by weak acidification. We compared the effects of various acids on the bactericidal activity of hypochlorite solution to establish a method for safe and effective use of an acidic hypochlorite solution.

METHODS AND RESULTS

The bactericidal activities of acidic hypochlorite solutions that had been adjusted to pH 5.0 with hydrochloric acid, acetic acid, citric acid, lactic acid, formic acid, phosphoric acid or sulphuric acid against Bacillus subtilis spores were compared. The acidic solutions prepared with hydrochloric acid and acetic acid showed the highest bactericidal activity, and all of the spores (5 x 106 cfu ml(-1)) were killed within 10 min. On the other hand, the solutions prepared with citric acid and lactic acid showed no bactericidal activity against any bacterial strains tested in this study despite the low pH. The amount of chlorine gas produced by the preparation using acetic acid was sixfold less than that produced from the preparation using hydrochloric acid.

CONCLUSIONS

Acetic acid is the most suitable and safe acid for the preparation of an acidic hypochlorite solution.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results of this study provide useful information for establishing a method for safe and effective use of an acidic hypochlorite solution.

Significantly rapid relief from steroid-resistant nephrotic syndrome by LDL apheresis compared with steroid monotherapy

Rapid amelioration of hypercholesterolemia by LDL apheresis (LDL-A) was performed for long-standing nephrotic syndrome (NS) with hyperlipidemia due to focal segmental glomerulosclerosis (FGS) and the clinical data and prognosis were compared between LDL-A-treated and nontreated groups. Seventeen steroid-resistant NS patients treated with LDL-A (LDL-A group) and 10 NS patients treated with steroids only (steroid-monotherapy (SM) group) were compared. Serum cholesterol and phospholipid levels were significantly lowered only in the LDL-A group (p < 0.01, respectively). The LDL-A group showed a significant decrease of urinary protein (UP, p < 0.01) and increase of serum albumin (p < 0.05). Average time needed to achieve a decrease of UP to less than nephrotic range (< 3.5 g/day) was significantly shorter in the LDL-A group than in the SM group (p < 0.01). Although this is not a prospective study, it is highly expected that a rapid improvement of hypercholesterolemia by LDL-A in steroid-resistant NS will provide more rapid relief from NS than steroid therapy alone.

Changes in 99mTechnegas ventilation lung scan in a newborn with absent pulmonary valve syndrome

A newborn infant with tetralogy of Fallot and absent pulmonary valve was successfully corrected in two stages. Absent pulmonary valve syndrome presenting in early infancy manifests severe respiratory symptoms that still make challenging both management and surgical treatment. This is ascribed to tracheobronchial compression by the extremely dilated pulmonary arteries, and to the resultant pulmonary obstructive lesions. We report herein the first findings of 99mTechnegas ventilation lung scanning in an infant with the syndrome to assess the pulmonary obstructive lesions.

Genetic variation in 16S-23S rDNA internal transcribed spacer regions and the possible use of this genetic variation for molecular diagnosis of Bacteroides species

The structural variation in 16S-23S rDNA internal transcribed spacer regions (ITS) among Bacteroides species was assessed by PCR amplification and sequencing analysis, and its possible use for molecular diagnosis of these species was evaluated. Ninety strains of the genus Bacteroides, including the species B. distasonis, B. eggerthii, B. fragilis, B. ovatus, B. thetaiotaomicron, B. uniformis and B. vulgatus, produced one to three ITS amplification products with sizes ranging from 615 to 810 bp. Some Bacteroides strains could be differentiated at species level on the basis of ITS amplification patterns and restriction fragment length polymorphism (RFLP) analysis using a four-nucleotide-recognizing enzyme, Msp I. The results of sequence analysis of ITS amplification products revealed genes for Ile-tRNA and Ala-tRNA in all strains tested. The nucleotide sequence, except for that in tRNA-coding regions, was highly variable and characteristic for each species, but a common sequence among B. fragilis, B. thetaiotaomicron and B. ovatus was observed. A digoxigenin-labeled oligonucleotide probe (named FOT1), which was designed from this conserved sequence, specifically hybridized to the ITS amplification products from B. fragilis, B. thetaiotaomicron and B. ovatus. These results suggest that the ITS region is a useful target for the development of rapid and accurate techniques for identification of Bacteroides species.

Acute pulmonary embolism resulting from cardiac tumors associated with tuberous sclerosis

A case report of a neonate with cardiac tumors in association with tuberous sclerosis is presented. The rare complication of pulmonary embolism and its successful treatment by anticoagulation and thrombolytic therapy is described. The treatment of these cardiac tumors is conservative, because the tumors regress spontaneously when the diagnosis is made in infancy. However, embolic event may rarely occur as a complication of cardiac tumors. If the cardiac tumors are treated conservatively, it is important to pay close attention to the occurrence of pulmonary embolism during the follow-up period.

Intraglomerular metastasis from pancreatic cancer

Few case reports have shown the presence of metastatic tumor cells in renal glomeruli. We report one case with intraglomerular metastasis proved at renal biopsy. A 60-year-old man suffered from weight loss and fever of unknown origin. Urinalysis revealed proteinuria with cellular and granular casts. Because vasculitis was suspected, renal biopsy was performed. Presence of tumor cells occupying the glomerular capillary lumina was shown by means of light microscopy and electron microscopy. Laboratory findings revealed elevated leukocyte count (28.9 x 10(3)/mm(3)), serum granulocyte colony-stimulating factor (G-CSF) (77 pg/mL), and serum CA 19-9 (21,885 U/mL). The patient soon developed disseminated intravascular coagulation and died. Autopsy findings revealed pancreatic cancer showing positive staining for G-CSF and CA 19-9. Tumor cells in the glomerular capillary lumina showed positive staining for CA 19-9 and proliferating cell nuclear antigen (PCNA). These results suggest that the pancreatic tumor cells producing G-CSF were entrapped in the glomerular capillary lumina where they proliferated. This may have been the first step in renal metastasis.

Outbreak of Chinese herb nephropathy in Japan: are there any differences from Belgium?

OBJECTIVE

The purpose of this article was to study and clarify the features of Chinese herb nephropathy (CHN) in Japan.

PATIENTS AND METHODS

The subjects consisted of patients diagnosed as having CHN in Saiseikai Nakatsu Hospital and of those reported in the literature in Japan. We investigated the clinical and histological features of CHN patients in Japan and compared them with the Belgian cases.

RESULTS

The remarkable differences were as follows: (1) high prevalence in males compared with Belgian cases, (2) Fanconi syndrome was found in most cases, (3) no patients had malignant tumors in the urinary tract. In addition, the ascribed Chinese medicines in Japan were divided into three groups: 'Tenshin-toki-shigyaku-ka-gosyuyu-syokyo-to', 'Boui-ougi-to', and others.

CONCLUSION

CHN in Japan has some characteristics distinguished from Belgian nephropathy. One hypothesis is a susceptibility to aristolochic acids (AAs), which is considered to be a causative agent, may be different among races. Another is that there could be some other toxic substances affecting the clinical findings although they are not identified at present. Further studies must be undertaken to clarify these differences.

Inhibitory effects of bitter melon (Momordica charantia Linn.) on bacterial mutagenesis and aberrant crypt focus formation in the rat colon

Antimutagenicity and chemopreventive activity of an 80%-ethanol extract of bitter melon (Momordica charantia Linn.) against the formation of azoxymethane (AOM)-induced aberrant crypt foci (ACF) was investigated. The bitter melon extract was nonmutagenic and inhibited the mutagenicity of heterocyclic amines 2-amino-3,4-dimethylimidazo[4,5-f]quinoline and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, and aflatoxin B1 in the Salmonella mutation assay. To examine the inhibitory effect of bitter melon on AOM-induced ACF formation, male F344 rats were fed various concentrations of the extract (0.1, 0.5, and 1.0 g/kg body weight) for five weeks during the initiation stage. One week after the administration of the plant extract, rats were subcutaneously given AOM at 15 mg/kg body weight once a week for two weeks. Three rats in each group were sacrificed 12 hr after the second AOM injection to analyze DNA adducts, O6-methylguanine (O6-meG) and N7-methylguanine in the liver and colon. The remaining rats were sacrificed 3 weeks after the second AOM injection to observe ACF. To examine the inhibitory effect of the extract on ACF formation in the postinitiation stage, rats were fed the extract at 0.1 and 1.0 g/kg body weight for 12 weeks starting two weeks after the second AOM injection. Treatment with bitter melon extract significantly inhibited ACF formation in the colon during the initiation stage and dose-dependently decreased the average of O6-meG DNA adduct in the colonic mucosa. During the postinitiation stage, bitter melon extract, at 1.0 g/kg body weight, significantly inhibited ACF formation in the colon, especially the formation of ACF with four or more crypts per focus. These findings suggest that bitter melon is a possible chemopreventive agent against colon carcinogenesis.

PCR-dot blot hybridization based on the neuraminidase-encoding gene is useful for detection of Bacteroides fragilis

Bacteroides fragilis is a Gram-negative obligate anaerobe frequently isolated from clinical specimens and sometimes causes severe septicemia in compromised hosts. Increasing interest has been shown in the enterotoxigenicity and drug resistance of B. fragilis in the field of medical microbiology. We previously reported rapid detection of this anaerobe by nested PCR targeting a neuraminidase-encoding gene nanH. In the present study, we synthesized a digoxigenin-labeled oligonucleotide probe, NH1, which is specific for nanH of B. fragilis, and we combined the hybridization assay using NH1 with the nanH-PCR to detect this anaerobe in a bacteremia model mice. In the specificity test, the oligonucleotide probe, NH1, hybridized only to amplification products from B. fragilis. PCR-dot blot hybridization based on nanH enabled detection of cells of B. fragilis in blood samples even when the number was as low as 2 x 10(3) colony-forming units/ml. These findings suggest that PCR-dot blot hybridization targeting nanH is a useful procedure for diagnosis of septicemia caused by B. fragilis when viable cells in blood cannot be detected by the traditional culture techniques.