Search for coherent charged pion production in neutrino-carbon interactions

We report the result from a search for charged-current coherent pion production induced by muon neutrinos with a mean energy of 1.3 GeV. The data are collected with a fully active scintillator detector in the K2K long-baseline neutrino oscillation experiment. No evidence for coherent pion production is observed, and an upper limit of is set on the cross section ratio of coherent pion production to the total charged-current interaction at 90% confidence level. This is the first experimental limit for coherent charged pion production in the energy region of a few GeV.

Evidence for muon neutrino oscillation in an accelerator-based experiment

We present results for nu(mu) oscillation in the KEK to Kamioka (K2K) long-baseline neutrino oscillation experiment. K2K uses an accelerator-produced nu(mu) beam with a mean energy of 1.3 GeV directed at the Super-Kamiokande detector. We observed the energy-dependent disappearance of nu(mu), which we presume have oscillated to nu(tau). The probability that we would observe these results if there is no neutrino oscillation is 0.0050% (4.0 sigma).

Theoretical Debye-Waller factors of alpha-MoO(3) estimated by an equation-of-motion method

EXAFS oscillations of MoO(3), which has a highly asymmetric local structure, have been calculated using backscattering amplitudes and phase shifts derived from the FEFF8 code and using Debye-Waller factors from an equation-of-motion method. They were compared with polarization-dependent empirical EXAFS data of the alpha-MoO(3) single crystal at various temperatures. The theoretical EXAFS oscillations of Mo-O bonds for the [001] direction of the single crystal, where two symmetric Mo-O bonds exist, reproduced well the experimental data. On the other hand, the calculated data for the [100] direction, which contain two asymmetric Mo-O bonds with different bond lengths, agree well with the experimental data only after adjustment of the amplitude reduction factors for different Mo-O bonds. EXAFS oscillations of MoO(3) powder were also calculated by the same method, and theoretical parameters that could reproduce the experimental data were found. These results suggest that the equation-of-motion method can evaluate the Debye-Waller factors efficiently in molecules with asymmetric local structures and can reduce curve-fitting parameters.

Gas6 rescues cortical neurons from amyloid beta protein-induced apoptosis

Gas6, a product of the growth-arrest-specific gene 6, protects neurons from serum deprivation-induced apoptosis. Neuronal apoptosis is also caused by amyloid beta protein (Abeta), whose accumulation in the brain is a characteristic feature of Alzheimer's disease. Abeta induces Ca(2+) influx via L-type voltage-dependent calcium channels (L-VSCCs), leading to its neurotoxicity. In the present study, we investigated effects of Gas6 on Abeta-induced cell death in primary cultures of rat cortical neurons. Abeta caused neuronal cell death in a concentration- and time-dependent manner. Gas6 significantly prevented neurons from Abeta-induced cell death. Gas6 ameliorated Abeta-induced apoptotic features such as the condensation of chromatin and the fragmentation of DNA. Prior to cell death, Abeta increased influx of Ca(2+) into neurons through L-VSCCs. Gas6 significantly inhibited the Abeta-induced Ca(2+) influx. The inhibitor of L-VSCCs also suppressed Abeta-induced neuronal cell death. The present cortical cultures contained few non-neuronal cells, indicating that Gas6 affected the survival of neurons directly, but not indirectly via non-neuronal cells. In conclusion, we demonstrate that Gas6 rescues cortical neurons from Abeta-induced apoptosis. Furthermore, the present study indicates that inhibition of L-VSCC contributes to the neuroprotective effect of Gas6.

Chiral autocatalysis, spontaneous symmetry breaking, and stochastic behavior

During the past decade, chirally autocatalytic systems that exhibit unusual and interesting phenomena, such as spontaneous chiral symmetry breaking and stochastic behavior, have been identified. In this Account we outline the context in which chiral autocatalysis is of interest, summarize recent advances, and discuss our current understanding of the underlying kinetics and mechanisms. In addition, we note some fundamental aspects of amplification of enantiomeric excess and sensitivity of symmetry breaking transitions to asymmetric factors.

Deterioration of axotomy-induced neurodegeneration by group IIA secretory phospholipase A2

Phospholipase A2 (PLA2) is proposed to play a role in the repair of the ruptured membrane after axotomy. In neonatal rats, we examined the effect of Group IIA secretory PLA2 (sPLA2-IIA) on axotomy-induced cell death of motoneurons. sPLA2-IIA significantly induced death of axotomized motoneurons. Indoxam, a specific inhibitor for sPLA2-IIA, protected motoneurons from the sPLA2-IIA-induced deterioration. The present study indicated that sPLA2-IIA possessed neurotoxic effect rather than neuroprotective effect against facial nerve.

Association of L* protein of Theiler's murine encephalomyelitis virus with microtubules in infected cells

We used an antibody raised against a synthetic peptide corresponding to amino acid residues 70-88 for characterizing the L* protein of Theiler's murine encephalomyelitis virus (TMEV), which is only synthesized in DA subgroup strains from an alternative AUG and is out of frame with the viral polyprotein; evidence suggests that L* protein is critical to viral persistence, demyelination, and growth in murine macrophage cell lines. It was synthesized with kinetics similar to that of other viral proteins, although less in amount. After synthesis, it remained stable in the cytoplasm and was not incorporated into virions. Immunofluorescent staining and immunoblotting of microtubule preparations demonstrated that it is associated with microtubules. Expression of L* protein also demonstrated that the 5' one third of the coding region may be responsible for the association. The association of L* protein with microtubules may be important in the disease-inducing and in vitro characters of L* protein.

Effects of S-2474, a novel nonsteroidal anti-inflammatory drug, on amyloid beta protein-induced neuronal cell death

1. The accumulation of amyloid beta protein (Abeta) in the brain is a characteristic feature of Alzheimer's disease (AD). Clinical trials of AD patients with nonsteroidal anti-inflammatory drugs (NSAIDs) indicate a clinical benefit. NSAIDs are presumed to act by suppressing inhibiting chronic inflammation in the brain of AD patients. 2. In the present study, we investigated effects of S-2474 on Abeta-induced cell death in primary cultures of rat cortical neurons. 3. S-2474 is a novel NSAID, which inhibits cyclo-oxygenase-2 (COX-2) and contains the di-tert-butylphenol antioxidant moiety. S-2474 significantly prevented neurons from Abeta(25 - 35)- and Abeta(1 - 40)-induced cell death. S-2474 ameliorated Abeta-induced apoptotic features such as the condensation of chromatin and the fragmentation of DNA completely. 4. Prior to cell death, Abeta(25 - 35) generated prostaglandin D(2) (PGD(2)) and free radicals from neurons. PGD(2) is a product of cyclo-oxygenase (COX), and caused neuronal cell death. 5. S-2474 significantly inhibited the Abeta(25 - 35)-induced generation of PGD(2) and free radicals. 6. The present cortical cultures contained little non-neuronal cells, indicating that S-2474 affected neuronal survival directly, but not indirectly via non-neuronal cells. Both an inhibitory effect of COX-2 and an antioxidant effect might contribute to the neuroprotective effects of S-2474. 7. In conclusion, S-2474 exhibits protective effects against neurotoxicity of Abeta. Furthermore, the present study suggests that S-2474 may possess therapeutic potential for AD via ameliorating degeneration in neurons as well as suppressing chronic inflammation in non-neuronal cells.

Conditions for chiral asymmetry generation in the preparation of the chiral octahedral cobalt complex

We have reported that the random chiral asymmetry generation, which is a spontaneous preferential generation of one enantiomer, was observed in the synthesis of a chiral octahedral cobalt complex, cis-[CoBr(NH(3))(en)(2)]Br(2). In this article, we review our studies to explain in this system the autocatalytic growth of small enantiomeric excess that arises due to statistical fluctuations. One important experimental finding was that the rate of chiral autocatalysis increased with increasing the degree of supersaturation. Furthermore, our numerical simulation indicates that even small inhomogeneities in the reaction system may play a significant role because their effect is amplified by the autocatalytic reaction under appropriate conditions. In a small volume, fluctuations in concentration can grow if the autocatalytic growth overcomes the diffusional loss of the excess concentration from this volume. This may makes the enantiomeric excess of the chiral complex randomly fluctuate from run to run.

Synthesis and structure–activity relationships of potent and orally active sulfonamide ETB selective antagonists

The synthesis and structure activity relationships of a series of N-pyrimidinyl benzenesulfonamides as ETB selective antagonists are described. N-Isoxazolyl benzenesulfonamide 1a, previously reported, (1) was selected as a lead compound, and isosteric replacement of the isoxazole ring of 1a with a pyrimidine ring led to the discovery of the highly potent ETB selective antagonist 6e with oral bioavailability. Modification of the terminal aldehyde group at the 6-position of the pyrimidine ring was investigated, and malonate 15b and acylhydrazone 16f were found to be equipotent to aldehyde 6e. Compound 6e showed ETB antagonistic activity on in vivo evaluation.

DXAFS study on the decarbonylation process of Mo(CO)6 in NaY supercages

The decarbonylation process of Mo(CO)6 in the NaY supercages was studied by means of a time resolved dispersive XAFS method during temperature programmed decarbonylation. XANES analysis demonstrated that the decarbonylation proceeded through two steps and that a stable intermediate existed between 440-490 K. The curve fitting analysis revealed that the intermediate was a molybdenum monomer subcarbonyl species coordinated by three CO ligands and three oxygen atoms of zeolite framework. Molybdenum dimer subcarbonyl species were not observed. This study demonstrated that DXAFS technique is a powerful method to study the dynamic behaviour of the Mo carbonyl species during decarbonylation process.

Telemedicine system using computed tomography van of high-speed telecommunication vehicle

The current medical system provides medical services to patients who visit hospitals. However, medical services can be provided at or close to the home of the patient using fully equipped mobile telemedicine systems. Such a system can identify the disease at an early stage, improve quality of life and prognosis through early diagnosis and treatment, and reduce the costs of medical service. Furthermore, the unit can provide mass screenings of the population, as well as full medical service to remote areas. The Telecommunications Advanced Organization of Japan, Matsumoto, Japan, and Shinshu University Hospital, Matsumoto, Japan, established a research center for a unique telemedicine project using a mobile system. The mobile unit consists of a van that houses a spiral computed-tomography (CT) machine and various telecommunications equipment. The unit allows medical examination, CT scanning, and on-line two-way transfer of image data/teleconferencing to a medical center for consultation with various specialists. We have used the system thus far for the early detection of lung cancer through mass screenings over a four-year period in 29 administrative districts. Mass screenings of 19117 residents resulted in the identification of 75 cases of early lung cancer who were later treated by partial pneumonectomy at Shinshu University Hospital and affiliated hospitals. We have also used the system to provide medical services to rural areas, as telemedicine support at remote areas, wintertime telemedicine support to an international sports competition, and various medical services to a home-care facility.

Development of an in situ polarization-dependent total-reflection fluorescence XAFS measurement system

An in situ polarization-dependent total-reflection fluorescence X-ray absorption fine structure (PTRF-XAFS) spectroscopy system has been developed, which enables PTRF-XAFS experiments to be performed in three different orientations at various temperatures (273-600 K) and pressures (10(-10) approximately 760 torr). The system consists of a measurement chamber and a preparation chamber. The measurement chamber has a high-precision six-axis goniometer and a multielement solid-state detector. Using a transfer chamber, also operated under ultra-high-vacuum conditions, the sample can be transferred to the measurement chamber from the preparation chamber, which possesses low-energy electron diffraction, Auger electron spectroscopy and X-ray photoelectron spectroscopy facilities, as well as a sputtering gun and an annealing system. The in situ PTRF-EXAFS for Cu species on TiO2 (110) has been measured in three different orientations, revealing anisotropic growth of Cu under the influence of the TiO2 (110) surface.

Time-resolved energy-dispersive XAFS study on the reduction process of Cu-ZSM-5 catalysts

The time-resolved reduction process of copper cations in ZSM-5 during temperature-programmed reduction (300-700 K) was studied by energy dispersive X-ray absorption fine structure (DXAFS). The Cu K-edge DXAFS spectra for isolated Cu2+ species in the channels of ZSM-5 were recorded at an interval of 1 s during the reduction. The curve fitting analysis of the EXAFS data and the XANES analysis revealed that the isolated Cu2+ species in the channels were reduced stepwise. They were reduced to isolated Cu+ species at 400-450 K and the Cu+ species to Cu0 metallic clusters at 550-650 K. Small clusters like Cu4 were initially formed, followed by particle growth. A small part of them went out to the outer surfaces of ZSM-5 during the reduction.

Three-dimensional analysis of the local structure of Cu on TiO2(110) by in situ polarization-dependent total-reflection fluorescence XAFS

Cu K-edge XAFS of Cu/TiO2(110) was measured by polarization-dependent total-reflection fluorescence XAFS technique. XAFS of [001], [110], and [110] directions were measured to elucidate the three dimensional structure of Cu species on the TiO2(110) surface prepared by the deposition of Cu(DPM)2 followed by reduction with H2. Simulation of the EXAFS functions as well as conventional curve fitting analysis revealed that plane Cu3,4 small clusters with similar structure to Cu(111) plane were formed by the reduction at 363 K. The small clusters converted into spherical metallic Cu particles by the reduction at 473 K.

Determining appropriate small vessels for stenting by intravascular ultrasound

To re-evaluate outcomes of stenting in small vessels, we studied 176 patients successfully treated with several types of stent by way of intravascular ultrasound (IVUS) and quantitative coronary angiography (QCA). These lesions were divided into 3 subgroups according to reference diameter (RD) by QCA, and vessel diameter (VD) by IVUS (group I: pre-RD 2.5 mm; group II: pre-RD < 2.5 mm and pre-VD 4.0 mm; group III: pre-RD < 2.5 mm and pre-VD < 4.0 mm). Post-procedure percent diameter stenosis (4 +/- 3%), post-procedure percent plaque area (42 +/- 3%), and loss index (39 +/- 11%) in group II were not significantly different from those in group I (7 +/- 2%, 37 +/- 2%, 45 +/- 5%, respectively). The rates of restenosis and target lesion revascularization in group II (24.0% and 16.0%, respectively) were not different from those in group I (25.9% and 21. 2%, respectively), and were significantly favorable compared to group III (66.7% and 39.4%, respectively; p < 0.05). By the use of IVUS, we not only identified those vessels which would normally go unstented when only using QCA, but also documented excellent long-term outcome in these patients.

Development of an X-ray photoemission electron microscopy system with multi-probes, and its application to surface imaging at static and dynamic states

We have developed a new X-ray photoemission electron microscopy system combined with low energy electron microscopy, photoemission electron microscopy, mirror electron microscopy (MEM), secondary electron emission microscopy (SEEM) and Auger electron emission microscopy, which provides multi-angle information on the distribution and change of element, chemical state, structure, etc. at solid surfaces under the working conditions such as high temperature and gas atmosphere. The performance of each microscopical method was examined and typical images are presented. The dynamic behaviour of fabricated surfaces has been imaged in real time by SEEM and MEM.

Mercury emissions from a coal-fired power plant in Japan

The emissions study for mercury was conducted at a 700 MW coal-fired plant for the combustion of three types of coal with mercury concentrations of 0.0063, 0.0367 and 0.065 mg/kg. The power plant is equipped with a cold-side electrostatic precipitator and wet type flue gas desulfurization system. During full load operation of the boilers, samples of the input and output streams such as coal, coal ash, ESP ash and post-ESP particulates and flue gas were collected. The Hg concentrations in solid were measured by cold-vapor atomic absorption spectrometry (AAS) after appropriate preparation and acid digestion. Gaseous Hg was collected using a mixed solution of potassium permanganate and sulfuric acid and the Hg concentrations in the samples were measured using cold-vapor AAS. The results were used to examine: (1) overall mass balances; (2) relative distribution in the power plant; (3) equilibrium of Hg species using MALT-2 calculation program; and (4) Hg concentrations in stack emissions. The mass balances estimated in this study were 100, 138 and 89%, respectively, for the coals. Total Hg concentrations in stack gas were 1.113, 0.422 and 0.712 microg(m3N), respectively, for the coals. More than 99.5% of the Hg in the stack emissions were in gaseous form and the proportion in particulate form was extremely low. The relative distribution of Hg in ESP, FGD and Stack ranged from 8.3 to 55.2%, 13.3 to 69.2% and 12.2% to 44.4%, respectively. The results indicated that factors other than the Hg concentration of coals and efficiency of pollution control devices might affect Hg emissions from coal-fired plant. The calculated equilibrium of the distribution of Hg species using the MALT2 program suggest that it is necessary to consider condensation mechanism to interpret the affect of Hg species on the variations of the removal efficiencies of Hg in the ESP.

Antibody-mediated remyelination: relevance to multiple sclerosis

Intravenous immunoglobulin (IVIG) is widely used for treatment of autoimmune neurological disorders and is currently in clinical trials as a therapy for multiple sclerosis. We have previously demonstrated that certain mouse monoclonal antibodies of the IgM isotype, promote significant remyelination when administered to mice with chronic Theiler's murine encephalomyelitis virus-induced demyelinating disease. These IgM antibodies bind to antigens expressed on oligodendrocytes. We now demonstrate that polyclonal human IgG (IVIG) and polyclonal human IgM also promote remyelination in this system. Although both polyclonal human IgG and IgM promote remyelination, IgM is more potent. Polyclonal human IgM also differs from human IgG in its ability to bind strongly to antigens expressed in the CNS and by oligodendrocytes. We propose that polyclonal IgG and polyclonal IgM may function to promote remyelination by different mechanisms. IVIG may function based on its immunomodulatory activity, while the activity of IgM is critically dependent upon its reactivity with CNS antigens. This possibility has clear relevance to the use of antibodies as a therapy for multiple sclerosis, suggesting that combined treatment with antibodies exerting immunomodulatory activity, in concert with antibodies that function through direct binding to CNS antigens, may synergize to enhance the efficacy of the therapy.

Relationship between infiltrating cells and adhesion molecules in the nasal mucosa of patients with allergic rhinitis

Antigen-induced changes of cell adhesion molecules and their relationships to infiltrating cells were investigated immunohistochemically in nasal mucosa of perennial allergic rhinitis patients. An increased expression of E-selectin and VCAM-1 was noted on the vascular endothelium of the nasal mucosa 15-25 h after the topical antigen challenge. Although there was no increased expression of ICAM-1, we noted a positive correlation between the expression of E-selectin and ICAM-1. The expression of E-selectin and VCAM-1 as well as ICAM-1 was revealed to be correlated with the number of EG2-positive cells and CD4-positive cells, but not with elastase-positive cells. These findings suggest that all these adhesion molecules play a role in the topical influxes of eosinophils and CD4-positive cells in allergic nasal mucosa.

Neurotrophin-4/5 promotes proliferation of oligodendrocyte-type-2 astrocytes (O-2A)

In this study, the ability of neurotrophin-5 (NT-4/5) to promote the proliferation of oligodendrocyte precursor (O-2A) cells has been examined. This has been accomplished by the addition of exogenous NT-4/5 to purified cultures of O-2A cells maintained in an undifferentiated state by the addition of the mitogens platelet derived growth factor (PDGF-AA) and basic fibroblast growth factor (bFGF). Counts of cells incorporating bromodeoxyuridine (BrdU) showed that the addition of NT-4/5 for 24 h increased O-2A cell proliferation by 1.8-fold above that seen in PDGF-AA and bFGF alone. These data demonstrate a previously unidentified role for the neurotrophin NT-4/5 in oligodendrocyte biology.

Effects of anti-VLA-4 monoclonal antibody treatment in murine model of allergic rhinitis

In order to study the role of VLA-4 in allergic rhinitis, the effects of anti-mouse VLA-4 monoclonal antibody (mAb) were evaluated in a murine model. BALB/c mice were sensitized first by i.p. injections (general sensitization) and then by daily nasal dripping of antigen (local sensitization) before performing a nasal antigen challenge. The mAb was applied either before the antigen challenge (BC group), before the local sensitization (BL group) or before the general sensitization (BS group). The effects were evaluated in terms of antigen-induced early-phase nasal symptoms (sneezing), late-phase nasal eosinophilia and the serum level of antigen-specific IgE. Antigen-induced nasal eosinophilia was significantly (p = 0.009) reduced in the BL group but not in the BC group (number of eosinophils = 114 +/- 15.1, 244 +/- 52.8 and 347 +/- 50.5 in the BL, BC and control groups, respectively). The serum level of the specific IgE was also significantly (p = 0.038) reduced in the BL group but not in the BC group (optical density = 1.18 +/- 0.07, 1.28 +/- 0.13 and 1.58 +/- 0.14 in the BL, BC and control groups, respectively). The suppressive effect on sneezing was not significant in either the BL or BC groups. In the BS group, suppressive effects on antigen-induced nasal responses and the specific IgE level were not statistically significant. These findings suggest that VLA-4 plays an important role in the topical booster or priming effects during repeated nasal antigen exposures in pre-sensitized animals.

Repeat intervention for in-stent restenosis: re-expansion of the initial stent is a predictor of recurrence of restenosis

BACKGROUND

In-stent restenosis has become a significant clinical problem as use of stents has increased. The optimal strategy for dealing with in-stent restenosis needs to be evaluated.

OBJECTIVE

To compare the acute and late results of interventions for in-stent restenosis according to the device used, and to analyze the clinical and procedural variables of the lesions treated and identify the determinants of recurrence of restenosis and target lesion revascularization (TLR).

METHODS

Procedural and late outcomes for 58 lesions in 50 patients who underwent repeat intervention for in-stent restenosis were analyzed. The results of interventions according to the device employed were compared. The predictors of recurrence of restenosis and TLR within 6 months were analyzed. The ratio of balloon diameter in repeat intervention to minimal lumen diameter after initial stenting (MLD0) was used as an index of re-expansion of stents. Serial intravascular ultrasound imaging was performed before and after repeat intervention for 33 lesions, and re-expansion of the initial stent was evaluated.

RESULTS

Repeat intervention was successful in treating all lesions. Angiographic follow-up was possible for 49 lesions (84%). The overall incidences of recurrence of restenosis and TLR were 40.1 and 27.6%, respectively. Despite the immediate results having been good, the late results of stenting for in-stent restenosis were not favorable. Diffuse-type in-stent restenosis, early in-stent restenosis, and balloon diameter:MLD0 ratio > 1.25 are independent predictors of poor late results. Intravascular ultrasound findings have shown that expansion of the initial stent leads to recurrence of restenosis and TLR.

CONCLUSIONS

Re-expansion of the initial stent can cause further vascular injury and there is a risk of recurrence of restenosis. Alternative therapeutic strategies that work without dilating the initial stent may be necessary for treating lesions with high risk of recurrence of restenosis.

alpha-eudesmol, a P/Q-type Ca(2+) channel blocker, inhibits neurogenic vasodilation and extravasation following electrical stimulation of trigeminal ganglion

In this study, we investigated the effect of alpha-eudesmol, which potently inhibits the presynaptic omega-agatoxin IVA-sensitive (P/Q-type) Ca(2+) channel, on neurogenic inflammation following electrical stimulation of rat trigeminal ganglion. Treatment with alpha-eudesmol (0.1-1 mg/kg. i.v.) dose-dependently attenuated neurogenic vasodilation in facial skin monitored by a laser Doppler flowmetry. In addition, alpha-eudesmol (1 mg/kg. i.v.) significantly decreased dural plasma extravasation in analysis using Evans blue as a plasma marker. On the other hand, alpha-eudesmol (1 mg/kg, i.v.) did not affect mean arterial blood pressure in rats. The calcitonin gene-related peptide (CGRP) and substance P (SP) released from activated sensory nerves have recently been suggested to be associated with the neurogenic inflammation. In this study, we also showed that alpha-eudesmol (0.45-45 microM) concentration-dependently inhibits the depolarization-evoked CGRP and SP release from sensory nerve terminals in spinal cord slices. These results indicate that the anti-neurogenic inflammation action of alpha-eudesmol, which does not affect the cardiovascular system, may be due to its presynaptic inhibition of the neuropeptide release from perivascular trigeminal terminals. We also suggest that the omega-agatoxin IVA-sensitive Ca(2+) channel blocker, alpha-eudesmol, may become useful for the treatment of the neurogenic inflammation in the trigemino-vascular system such as migraine.

Human monoclonal antibodies reactive to oligodendrocytes promote remyelination in a model of multiple sclerosis

Promoting remyelination, a major goal of an effective treatment for demyelinating diseases, has the potential to protect vulnerable axons, increase conduction velocity, and improve neurologic deficits. Strategies to promote remyelination have focused on transplanting oligodendrocytes (OLs) or recruiting endogenous myelinating cells with trophic factors. Ig-based therapies, routinely used to treat a variety of neurological and autoimmune diseases, underlie our approach to enhance remyelination. We isolated two human mAbs directed against OL surface antigens that promoted significant remyelination in a virus-mediated model of multiple sclerosis. Four additional OL-binding human mAbs did not promote remyelination. Both human mAbs were as effective as human i.v. Ig, a treatment shown to have efficacy in multiple sclerosis, and bound to the surface of human OLs suggesting a direct effect of the mAbs on the cells responsible for myelination. Alternatively, targeting human mAbs to areas of central nervous system (CNS) pathology may facilitate the opsonization of myelin debris, allowing repair to proceed. Human mAbs were isolated from the sera of individuals with a form of monoclonal gammopathy. These individuals carry a high level of monoclonal protein in their blood without detriment, lending support to the belief that administration of these mAbs as a therapy would be safe. Our results are (i) consistent with the hypothesis that CNS-reactive mAbs, part of the normal Ig repertoire in humans, may help repair and protect the CNS from pathogenic immune injury, and (ii) further challenge the premise that Abs that bind OLs are necessarily pathogenic.

Preferential expression of myelencephalon-specific protease by oligodendrocytes of the adult rat spinal cord white matter

Myelencephalon-specific protease (MSP) is a novel serine protease that is expressed predominantly in the nervous system. In the adult rat spinal cord, MSP mRNA expression was dramatically upregulated, in both the white and gray matter, after systemic exposure to the glutamate receptor agonist, kainic acid (KA) (Scarisbrick et al. J Neurosci 17: 8156-8168, 1997b). To determine the cell-specific expression patterns of MSP, we generated MSP-specific monoclonal antibodies. These have been used in immunohistochemical and in situ hybridization colocalization studies, to demonstrate that MSP mRNA and protein are produced predominantly by CNP-immunoreactive oligodendroglia, but not by GFAP-immunoreactive astrocytes, in the white matter of the normal adult cord. In vitro, the soma of oligodendrocytes were also densely MSP immunoreactive, as were their growth tips, while astrocytes were associated with lower levels. These findings suggest that the enzymatic activity of MSP is likely to be important in the biology of oligodendrocytes and/or in the maintenance of the nerve fiber tracts of the adult spinal cord.

omega-agatoxin IVA-sensitive Ca(2+) channel blocker, alpha-eudesmol, protects against brain injury after focal ischemia in rats

omega-Agatoxin IVA-sensitive Ca(2+) channels have been thought to be involved in physiological excitatory amino acid glutamate release and these channels may also contribute to the development of ischemic brain injury. Recently, we demonstrated that alpha-eudesmol from Juniperus virginiana Linn. (Cupressaceae) inhibits potently the presynaptic omega-agatoxin IVA-sensitive Ca(2+) channels. In the present study, we investigated the effects of alpha-eudesmol on brain edema formation and infarct size determined after 24 h of reperfusion following 1 h of middle cerebral artery occlusion in rats. We first found that alpha-eudesmol concentration-dependently inhibited glutamate release from rat brain synaptosomes and that its inhibitory effect was Ca(2+)-dependent. In the middle cerebral artery occlusion study, intracerebroventricular (i.c.v.) treatment with alpha-eudesmol significantly attenuated the post-ischemic increase in brain water content. alpha-Eudesmol also significantly reduced the size of the infarct area determined by triphenyltetrazolium chloride staining after 24 h of reperfusion. Using a microdialysis technique, we further demonstrated that alpha-eudesmol inhibits the elevation of the extracellular concentration of glutamate during ischemia. From these results, we suggest that alpha-eudesmol displays an ability to inhibit exocytotic glutamate release and to attenuate post-ischemic brain injury.

Accelerated radiotherapy for T1, 2 glottic carcinoma: analysis of results with KI-67 index

PURPOSE

Hyperfractionated and accelerated radiotherapy without a split was performed to improve the local control probability of early glottic carcinomas. We analyzed the results of this regimen by using the Ki-67 index.

METHODS AND MATERIALS

Over a 12-year period, 85 T1N0M0 glottic cancers and 50 T2N0M0 glottic cancers were treated with conventional fractionation (CF) from 1984 to 1989 and with accelerated fractionation (AF) since 1990. The CF program consisted of five daily fractions of 2 Gy per week, for a total of 64 Gy. The AF program consisted of 1.72 Gy per fraction, two fractions per day, 5 days a week, for a total of 55 or 58 Gy. The specimens, taken before radiotherapy, were immunohistochemically stained with anti-Ki-67 antibody.

RESULTS

The 5-year local control probability for T1 tumors was 79.6 +/- 6.9% with CF treatment, whereas with AF it was 86.9 +/- 5.6%. For T2 tumors it was 62.7 +/- 12.2% with CF, whereas it was 74.7 +/- 7.8% with AF. The difference between CF and AF did not reach the point of statistical significance. However, when T1 tumors had a Ki-67 index lower than 50%, the local control rate achieved with AF was significantly better than that with CF (p = 0.018). When the tumors had a Ki-67 index that was 50% or more, there was no difference in the local control rate between CF and AF, whether they were T1 or T2. The peak mucosal reactions at the larynx and/or hypopharynx were much more severe and appeared at smaller doses and earlier in AF than in CF. The patients with AF showed no severe late complications.

CONCLUSIONS

AF could not obtain statistically significant improvement in local control probability of T1 or T2 glottic carcinomas.

Effect of CT digital image compression on detection of coronary artery calcification

PURPOSE

To test the effect of digital compression of CT images on the detection of small linear or spotted high attenuation lesions such as coronary artery calcification (CAC).

MATERIAL AND METHODS

Fifty cases with and 50 without CAC were randomly selected from a population that had undergone spiral CT of the thorax for screening lung cancer. CT image data were compressed using JPEG (Joint Photographic Experts Group) or wavelet algorithms at ratios of 10:1, 20:1 or 40:1. Five radiologists reviewed the uncompressed and compressed images on a cathode-ray-tube. Observer performance was evaluated with receiver operating characteristic analysis.

RESULTS

CT images compressed at a ratio as high as 20:1 were acceptable for primary diagnosis of CAC. There was no significant difference in the detection accuracy for CAC between JPEG and wavelet algorithms at the compression ratios up to 20:1. CT images were more vulnerable to image blurring on the wavelet compression at relatively lower ratios, and "blocking" artifacts occurred on the JPEG compression at relatively higher ratios.

CONCLUSION

JPEG and wavelet algorithms allow compression of CT images without compromising their diagnostic value at ratios up to 20:1 in detecting small linear or spotted high attenuation lesions such as CAC, and there was no difference between the two algorithms in diagnostic accuracy.

Evaluation of scaffolding effects of five different types of stents by intravascular ultrasound analysis

The acute elastic recoil of 5 types of stents immediately after deployment by intravascular ultrasound and quantitative coronary angiography measurements was analyzed. Successfully implanted stents were: Palmaz-Schatz in 104 lesions, Gianturco-Roubin in 65, Wiktor in 45, gfx in 22, and Multi-Link stents in 22. Before and after stenting, the cross section of the smallest luminal area and vessel area was measured with intravascular ultrasound. The postdilatation balloon area was calculated by quantitative coronary angiography. Percent recoil was calculated as: [1-(preluminal area)/balloon area)] x 100. The ratio of balloon area-to-vessel area was also compared. Although preluminal areas in Gianturco-Roubin and Palmaz-Schatz stents were similar (2.4 +/- 0.1 vs 2.5 +/- 0.1 mm2, p = NS), postluminal area in the Gianturco-Roubin was significantly smaller than the area in the Palmaz-Schatz (6.3 +/- 0.2 vs 8.3 +/- 0.3 mm2, p <0.05). Although both the balloon area/vessel area (0.68 +/- 0.05, 0.80 +/- 0.08 vs 0.83 +/- 0.02, p <0.05) and the preluminal area (2.1 +/- 0.4, 1.6 +/- 0.2 vs 2.5 +/- 0.1 mm2, p <0.05) were smaller in gfx and Multi-Link than in the Palmaz-Schatz, postluminal area was comparable to the area in the Palmaz-Schatz (7.8 +/- 0.4, 7.4 +/- 0.4 vs 8.3 +/- 0.3 mm2, p = NS). Percent recoil in the Gianturco-Roubin was poorest among these 5 groups. More favorable initial gain can be obtained with Palmaz-Schatz, Wiktor, gfx, and Multi-Link stents than with the Gianturco-Roubin stent.

Internalization and sorting of plasma membrane sphingolipid analogues in differentiating oligodendrocytes

We studied the formation of early endosomes in differentiating oligodendrocytes and type-2 astrocytes, which are derived from common precursor cells in rat neonates, using fluorescent analogues of lactosylceramide (LacCer) and sulfatide labeled with 4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene++ +-3-pentanoic acid (BODIPY FL C5). These sphingolipid analogues exhibit a concentration-dependent shift in their fluorescence emission maximum from green to red wavelengths that can be used to estimate the relative concentration of an analogue in the intracellular membranes of living cells by quantitative fluorescence microscopy. When oligodendrocytes at various stages of differentiation were incubated with 1 microM BODIPY-sphingolipid at 10 degrees C and washed, yellow/green plasma membrane fluorescence was observed. Quantitative studies confirmed that the amount of BODIPY-LacCer or -sulfatide incorporated into the plasma membrane of a given cell type was identical. When these cells were subsequently warmed to 37 degrees C for 2-10 min to allow internalization to occur, the BODIPY-sphingolipid analogues were distributed in a punctate pattern throughout the cytoplasm. Within individual cells labeled with BODIPY-sulfatide, some endosomes exhibited green fluorescence, whereas others emitted red/orange fluorescence. In contrast, when BODIPY-LacCer was used, only green endosomes were observed. Although this phenomenon could be observed at earlier stages of differentiation, it was most obvious in mature oligodendrocytes, where quantitative measurements of the red/green ratio of individual endosomes suggested about a threefold difference between the concentration of the LacCer and sulfatide analogues in endosomes. These results suggest that "lipid sorting" takes place during endocytosis in mature oligodendrocytes, resulting in selective exclusion of certain lipid species during the internalization process. This sorting event may result in the net addition of lipids to the differentiated oligodendrocyte plasma membrane.

Successful stenting on tortuous coronary artery with accordion phenomenon: strategy--a case report

Guidewire manipulation through tortuosities is difficult. Straightening a tortuous coronary artery by using a stiff guidewire has been recognized to induce vessel wall shortening referred to as an "accordion phenomenon." With inappropriate identification as dissection or thrombus formation, the risk of performing unnecessary dilation at the pseudo-narrowing site exists. The authors describe here two cases showing the accordion phenomenon induced by a stiff guidewire during successful stenting at a tortuous right coronary artery. In another case, the authors experienced an "accordion phenomenon" at the proximal edge of the Palmaz-Schatz stent implanted in a tortuous right coronary artery. The stent edge was better positioned at the straight portion than at the contour portion in a tortuous coronary artery.

Detection of small peripheral lung cancer by digital chest radiography. Performance of unprocessed versus unsharp mask-processed images

PURPOSE

To clarify whether processed digital chest radiography can improve the detection rate for small peripheral lung cancer.

MATERIAL AND METHODS

Five radiologists independently interpreted 54 digitized chest radiographs of 18 patients with small peripheral lung cancers measuring less than 20 mm, which were displayed following 3 types of digital processing: 1) an original version; 2) unsharp mask processing with a type 1 filter (very low-frequency-enhancing, mid-frequency-suppressing, and high-frequency-enhancing filter); and 3) unsharp mask processing with a type 2 filter (very low- and high-frequency-enhancing filter). A total of 1,620 pooled observations were evaluated by receiver operating characteristic (ROC) analysis.

RESULTS

The mean area under the ROC curves was 0.68 for the type 1 filter, 0.68 for the type 2 filter, and 0.65 for the unprocessed (original) image. There were no statistically significant differences among these 3 kinds of image processing (p>0.05). In all types of images, the small lung cancer with an alveolar lining tumor growth was less visible than a solid tumor growth (p<0.01); the sensitivity increased with tumor size when the 3 groups of cancers, those measuring less than 10 mm, 11-15 mm, and 16-20 mm, were compared (p<0.01).

CONCLUSION

Unsharp mask-image processing of digital chest radiography will not improve the detection rate of small peripheral lung cancer, probably due to a substantial drawback: the limited conspicuity of cancer lesions in the surrounding lung and superposition of structures.

Angioplasty/bypass combination therapy in an 89-year-old man with left main trunk disease

We report a case of an 89-year-old man presenting with unstable angina and left main trunk disease. Minimally invasive direct coronary artery bypass grafting supplemented by catheter intervention was successfully performed. In view of the increasing elderly population, angioplasty/bypass combination therapy may be an important alternative for elderly coronary artery disease patients.

Stretch-activated ion channel blocker gadolinium attenuates ischemic ST-segment elevation in canine myocardium

Regional transmural ischemia causes both ST-segment elevation and systolic elongation (bulging) of the myocardium. Mechanical stretch might alter the transmembrane potential via stretch-activated ion channels (SAC); however, the role of SAC on ischemic ST-segment elevation has not yet fully studied. The present study investigated the role of SAC in the genesis of ischemic ST-segment elevation in the in-vivo canine heart. In 6 anesthetized dogs, an extracorporeal conduit connected to the left anterior descending coronary artery was occluded for 5 min before and after the intracoronary infusion of gadolinium (Gd, 500 micromol/min). To eliminate the effect of ischemic preconditioning, the bypass was occluded for 5 min before the experiment. Percent systolic shortening (%SS) and percent systolic elongation (%bulging) were measured using a pair of ultrasonic dimension crystals. A unipolar epicardial ECG was monitored at the center of the ischemic area for the measurement of the ST-segment level. At the end of coronary occlusion, there was no difference in the reduction of %SS or the increase of %bulging between before and after infusion of Gd. ST-segment elevation, however, was significantly attenuated by the infusion of Gd. These data demonstrated that the activation of SAC is one cause of ischemic ST-segment elevation.