Measurements of Strong-Interaction Effects in Kaonic-Helium Isotopes at Sub-eV Precision with X-Ray Microcalorimeters.

We have measured the 3d→2p transition x rays of kaonic ^{3}He and ^{4}He atoms using superconducting transition-edge-sensor microcalorimeters with an energy resolution better than 6 eV (FWHM). We determined the energies to be 6224.5±0.4(stat)±0.2(syst) eV and 6463.7±0.3(stat)±0.1(syst) eV, and widths to be 2.5±1.0(stat)±0.4(syst) eV and 1.0±0.6(stat)±0.3(stat) eV, for kaonic ^{3}He and ^{4}He, respectively. These values are nearly 10 times more precise than in previous measurements. Our results exclude the large strong-interaction shifts and widths that are suggested by a coupled-channel approach and agree with calculations based on optical-potential models.

Precise Measurement of Differential Cross Sections of the Σ

The differential cross sections of the Σ^{-}p→Λn reaction were measured accurately for the Σ^{-} momentum (p_{Σ}) ranging from 470 to 650 MeV/c at the J-PARC Hadron Experimental Facility. Precise angular information about the Σ^{-}p→Λn reaction was obtained for the first time by detecting approximately 100 reaction events at each angular step of Δcosθ=0.1. The obtained differential cross sections show a slightly forward-peaking structure in the measured momentum regions. The cross sections integrated for -0.7≤cosθ≤1.0 were obtained as 22.5±0.68 [statistical error(stat.)] ±0.65 [systematic error(syst.)] mb and 15.8±0.83(stat)±0.52(syst) mb for 470

First Determination of the Level Structure of an sd-Shell Hypernucleus, _{Λ}

We report on the first observation of γ rays emitted from an sd-shell hypernucleus, _{Λ}^{19}F. The energy spacing between the ground state doublet, 1/2^{+} and 3/2^{+} states, of _{Λ}^{19}F is determined to be 315.5±0.4(stat)_{-0.5}^{+0.6}(syst) keV by measuring the γ-ray energy of the M1(3/2^{+}→1/2^{+}) transition. In addition, three γ-ray peaks are observed and assigned as E2(5/2^{+}→1/2^{+}), E1(1/2^{-}→1/2^{+}), and E1(1/2^{-}→3/2^{+}) transitions. The excitation energies of the 5/2^{+} and 1/2^{-} states are determined to be 895.2±0.3(stat)±0.5(syst) and 1265.6±1.2(stat)_{-0.5}^{+0.7}(syst) keV, respectively. It is found that the ground state doublet spacing is well described by theoretical models based on existing s- and p-shell hypernuclear data.

Nuclear Force Imprints Revealed on the Elastic Scattering of Protons with

How does nature hold together protons and neutrons to form the wide variety of complex nuclei in the Universe? Describing many-nucleon systems from the fundamental theory of quantum chromodynamics has been the greatest challenge in answering this question. The chiral effective field theory description of the nuclear force now makes this possible but requires certain parameters that are not uniquely determined. Defining the nuclear force needs identification of observables sensitive to the different parametrizations. From a measurement of proton elastic scattering on ^{10}C at TRIUMF and ab initio nuclear reaction calculations, we show that the shape and magnitude of the measured differential cross section is strongly sensitive to the nuclear force prescription.

Observation of Spin-Dependent Charge Symmetry Breaking in ΛN Interaction: Gamma-Ray Spectroscopy of _{Λ}

The energy spacing between the spin-doublet bound state of _{Λ}^{4}He(1^{+},0^{+}) was determined to be 1406±2±2 keV, by measuring γ rays for the 1^{+}→0^{+} transition with a high efficiency germanium detector array in coincidence with the ^{4}He(K^{-},π^{-})_{Λ}^{4}He reaction at J-PARC. In comparison to the corresponding energy spacing in the mirror hypernucleus _{Λ}^{4}H, the present result clearly indicates the existence of charge symmetry breaking (CSB) in ΛN interaction. By combining the energy spacings with the known ground-state binding energies, it is also found that the CSB effect is large in the 0^{+} ground state but is vanishingly small in the 1^{+} excited state, demonstrating that the ΛN CSB interaction has spin dependence.

Evidence of soft dipole resonance in

The first conclusive evidence of a dipole resonance in ^{11}Li having isoscalar character observed from inelastic scattering with a novel solid deuteron target is reported. The experiment was performed at the newly commissioned IRIS facility at TRIUMF. The results show a resonance peak at an excitation energy of 1.03±0.03 MeV with a width of 0.51±0.11 MeV (FWHM). The angular distribution is consistent with a dipole excitation in the distorted-wave Born approximation framework. The observed resonance energy together with shell model calculations show the first signature that the monopole tensor interaction is important in ^{11}Li. The first ab initio calculations in the coupled cluster framework are also presented.

Search for the Θ+ pentaquark via the π(-)p→K(-)X reaction at 1.92 GeV/c.

The Θ(+) pentaquark baryon was searched for via the π(-)p→K(-)X reaction with a missing mass resolution of 1.4 MeV/c(2) (FWHM) at the Japan Proton Accelerator Research Complex (J-PARC). π(-) meson beams were incident on the liquid hydrogen target with a beam momentum of 1.92 GeV/c. No peak structure corresponding to the Θ(+) mass was observed. The upper limit of the production cross section averaged over the scattering angle of 2° to 15° in the laboratory frame is obtained to be 0.26 µb/sr in the mass region of 1.51-1.55 GeV/c(2). The upper limit of the Θ(+) decay width is obtained to be 0.72 and 3.1 MeV for J(Θ)(P)=1/2(+) and J(Θ)(P)=1/2(-), respectively, using the effective Lagrangian approach.

Histopathological differences in bony destruction of malleus and incus following mastoidectomy.

OBJECTIVES: Upon direct inspection of surgically removed ossicles from the ears of patients with long-term post-mastoidectomy cavity problems, the extent of malleus destruction often appears greater in patients with a longer duration of cavity problems, whereas the extent of incus destruction does not appear to correlate with the duration of cavity problems. This study aimed to investigate this impression. MATERIALS AND METHODS: As a result of total middle-ear reconstruction, 41 ossicles (21 malleus and 20 incus bones) were obtained from 31 patients with post-mastoidectomy cavity problems. The ossicles were examined histopathologically, and the proportion of lamellar bone area to total bone area (expressed as percentage lamellar bone) was measured. We also calculated the inter-operation time, i.e. the time period between the previous mastoidectomy and the recent total middle-ear reconstruction; this parameter was used as an approximate measure of the duration of the patient's cavity problem. Correlations between percentage lamellar bone and inter-operation time were calculated for the two ossicles. RESULTS: The range of inter-operation times was seven to 65 years. We observed a correlation between percentage lamellar bone and inter-operation time for malleus bones (r = -0.512, p < 0.05), but not for incus bones. CONCLUSION: These results were in agreement with our pre-study impressions.

Measurement of Parity Violation in np Capture: the NPDGamma Experiment.

The NPDGamma experiment will measure the parity-violating directional gamma ray asymmetry A γ in the reaction [Formula: see text]. Ultimately, this will constitute the first measurement in the neutron-proton system that is sensitive enough to challenge modern theories of nuclear parity violation, providing a theoretically clean determination of the weak pion-nucleon coupling. A new beam-line at the Los Alamos Neutron Science Center (LANSCE) delivers pulsed cold neutrons to the apparatus, where they are polarized by transmission through a large volume polarized (3)He spin filter and captured in a liquid para-hydrogen target. The 2.2 MeV gamma rays from the capture reaction are detected in an array of CsI(Tl) scintillators read out by vacuum photodiodes operated in current mode. We will complete commissioning of the apparatus and carry out a first measurement at LANSCE in 2004-05, which would provide a statistics-limited result for A γ accurate to a standard uncertainty of ±5 × 10(-8) level or better, improving on existing measurements in the neutron-proton system by a factor of 4. Plans to move the experiment to a reactor facility, where the greater flux would enable us to make a measurement with a standard uncertainty of ±1 × 10(-8), are actively being pursued for the longer term.

Commissioning of the NPDGamma Detector Array: Counting Statistics in Current Mode Operation and Parity Violation in the Capture of Cold Neutrons on B 4 C and (27) Al.

The NPDGamma γ-ray detector has been built to measure, with high accuracy, the size of the small parity-violating asymmetry in the angular distribution of gamma rays from the capture of polarized cold neutrons by protons. The high cold neutron flux at the Los Alamos Neutron Scattering Center (LANSCE) spallation neutron source and control of systematic errors require the use of current mode detection with vacuum photodiodes and low-noise solid-state preamplifiers. We show that the detector array operates at counting statistics and that the asymmetries due to B4C and (27)Al are zero to with- in 2 × 10(-6) and 7 × 10(-7), respectively. Boron and aluminum are used throughout the experiment. The results presented here are preliminary.

Spallation ultracold-neutron production in superfluid helium.

The first ultracold-neutron (UCN) production in superfluid helium placed in a spallation neutron source is carried out. A UCN density of 0.7 UCN/cm(3), which can be used in experiments, is achieved for a proton-beam power of 78 W and a He-II temperature of 1.2 K. The present new UCN source is not limited by Liouville's theorem and extraction losses, which were serious problems in the previous sources. The present source has the possibility of extremely high-density UCN production compared with previous UCN sources.

Identification of dual specificity phosphatases induced by olfactory bulbectomy in rat olfactory neuroepithelium.

Dual specificity protein tyrosine phosphatases (dsPTPs) are a subfamily of protein tyrosine phosphatases implicated in the regulation of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK), and p38 mitogen-activated protein kinases (MAPKs) which are target enzymes activated by a wide range of cell-surface stimuli. Like these kinases, a class of dsPTP has been implicated in cell differentiation, regeneration, and apoptosis. In order to isolate dsPTPs which might play an important role in neuronal regeneration and apoptosis in olfactory neuroepithelium, we subcloned DNA fragments amplified by reverse transcription-polymerase chain reaction (RT-PCR), using degenerate oligonucleotide primers based on the conserved amino acid regions within the catalytic domain of dsPTPs, from rat olfactory epithelial RNA 1 and 4 h after an olfactory bulbectomy. The PCR products were subcloned into the pCRII vector, and 23 clones were chosen for further characterization. The sequence of these 23 individual clones revealed that two clones were identical to the rat dsPTP, MKP-3, and the other 21 clones were identical to the rat dsPTP, MKP-1. By Northern analysis, the MKP-1 transcript was induced and peaked 4 h following a bulbectomy. Similar results were obtained with the MKP-3 transcript. These results suggest that MKP-1 and MKP-3 may be involved in the early steps of apoptosis in vivo in rat olfactory neuroepithelium.

Fungal mastoiditis in an immunocompetent adult.

Manifest fungal infection of the middle ear, fungal mastoiditis, is a very rare entity, which is almost exclusively seen in immunocompromised patients. The authors present a case of fungal mastoiditis in a 52-year-old woman without immunocompromise. The patient presented with acutely progressing symptoms of hearing loss and dysequilibrium. Bony fistula of the semicircular canal was noted on CT scans and a marginal perforation of the tympanic membrane was also seen. Her hearing recovered following the surgery, which revealed massive granulations and proliferation of fungi but no cholesteatoma in the mastoid cavity. Fungal infection of the middle ear is rare, but can cause serious complications. The possibility should be considered even in immunocompetent patients.

Narrow internal auditory meatus: an idiopathic case confirming the origin and pathway of vestibular evoked myogenic potentials in humans.

OBJECTIVE: To confirm the origin and pathway of vestibular evoked myogenic potentials (VEMPs) in humans. DESIGN: Case study. SETTING: University hospital. PATIENT: A patient with a narrow internal auditory meatus (IAM). MAIN OUTCOME MEASURES: Imaging studies and functional studies concerning the seventh and eighth cranial nerves. RESULTS: Of the 4 nerves in the IAM, all but the cochlear nerve had normal function and normal courses, despite the pronounced narrowing of the IAM. The facial nerve had a normal diameter, but the vestibular nerves were thinner. Imaging revealed that the cochlear nerve was absent or extremely thinned. Both the cochlea and the cochlear nerve showed no function in the affected ear, although the VEMPs were evoked normally. CONCLUSION: Our results definitively support the vestibular origin of VEMPs in humans.

Evaluation of the role of human retinal vascular endothelial cells in the pathogenesis of CMV retinitis.

Previous studies of cytomegalovirus (CMV) retinitis have failed to definitively explain the exact mechanism by which CMV gains access to and initiates infection in the retina. Proposed theories have included leakage of the virus through vessels with altered permeability, with subsequent infection of surrounding glial cells. In an attempt to shed further light on this subject, a histopathologic examination of 30 autopsy eyes from patients with known systemic CMV disease was carried out using light microscopy, immunohistochemical and immunofluorescent techniques, and in-situ hybridization. Dual-staining methods were used to identify the exact cell type showing the presence of CMV antigens, namely vascular endothelial cells, glial cells, neuronal cells, and/or leukocytes. In those eyes with CMV retinitis, the sites of full-thickness retinal necrosis revealed viral presence mostly within Müller cells and perivascular glial cells, with focal areas of positive staining within retinal pigment epithelial cells (RPE) and neuronal cells. The retinal capillaries were devoid of endothelial cells in these areas. Adjacent to regions of full-thickness necrosis, some vessels showed the presence of a viral antigen within the endothelial cells. These findings suggest that retinal vascular endothelial cells can be infected with CMV. It can further be hypothesized that infection of vascular endothelial cells leads to infection of the surrounding glial and neuronal cells, with eventual spread to the RPE. Endothelial cells might not be present in areas of full-thickness necrosis due to mechanical forces from adjacent blood flow resulting in the sloughing of these cells.

[A case of hereditary sensory autonomic neuropathy type II with late onset].

We reported a 22-year-old man with hereditary sensory autonomic neuropathy (HSAN) type II. His initial neurological symptom at the age of 18 years was hypoesthesia on the feet and legs. In spite of late onset and absence of multilating acropathy, we diagnosed this case as HSAN type II because of an absence of sensory nerve action potentials with normal motor nerve conduction velocities and of a total loss of myelinated fibers with a decrease of unmyelinated fibers in the sural nerve. The sweating induced by iontophoretic pilocarpine stimulation was decreased on the dorsum of the foot. In addition, the morphometric analysis of sudomotor nerves around sweat glands showed a decrease of nerve terminals and unmyelinated axons. Because decrease or loss of sweating is one of the cardinal signs in HSAN type II, the quantitative sweating test and morphometric evaluation of the innervation of sweat glands are important for the proof of the autonomic signs.

Induction of KGF, basic FGF, and TGFalpha mRNA expression during healing of experimental TM perforations.

KGF (KGF), synthesized and secreted exclusively by stromal cells in epithelialized organs, specifically promotes proliferation of cells of epithelial origin, including keratinocytes. A related peptide, basic fibroblast growth factor (bFGF), has mitogenic properties for fibroblasts and endothelial cells. KGF expression is stimulated markedly in the skin during wound healing. To investigate the physiologic action of KGF in the healing of TM (TM) perforations, we examined KGF and KGF receptor (KGFR) mRNA transcript levels as well as those of bFGF and transforming growth factor-alpha (TGFalpha) in normal and wounded rat TM at varying intervals, using a semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). We found KGF and TGFalpha mRNA expression to be induced rapidly, peaking 3 days after wounding and then declining. Expression of bFGF was induced gradually and remained increased until 7 days. In contrast, we found KGFR to be expressed in normal TM, remaining unchanged during TM repair. These results indicate that KGF and TGFalpha may mediate migration and proliferation of epithelial cells of the outer layer in the early stage of TM repair while bFGF may mediate the connective tissue reaction in the middle layer in a subsequent stage.

Keratinocyte growth factor and its receptor messenger RNA expression in nasal mucosa and nasal polyps.

To examine the potential biologic role of fibroblast growth factors (FGFs) in nasal polyps and nasal mucosa during chronic inflammatory conditions, we investigated messenger RNA (mRNA) expression of three members of the FGF family -- acidic FGF, basic FGF, and keratinocyte growth factor (KGF)-- in nasal polyp tissues, as well as in hyperplastic nasal mucosa. Using the sensitive method reverse transcription-polymerase chain reaction (RT-PCR), we demonstrated that of the examined FGFs, KGF had the most abundant mRNA expression in nasal polyps and nasal mucosa. We also found that significantly higher levels of KGF mRNA were expressed in nasal polyps than in nasal mucosa, whereas mRNA expression of acidic FGF and basic FGF was relatively low in these tissues. In addition, we showed that KGF receptor mRNA was present in most of the nasal mucosa; however, none or little was expressed in nasal polyps. These results suggest that KGF might play an important role in nasal epithelial proliferation and that excessive synthesis of KGF in nasal polyp stroma may contribute to hypertrophy of the nasal mucosa in patients with chronic sinusitis associated with nasal polyposis.

Antigen-presenting cells in experimental autoimmune uveoretinitis.

The present study attempts to identify the antigen-presenting cells in the retina, utilizing bone marrow-transplanted chimeric rats. Two types of chimeras were used: one produced by transplanting bone marrow cells from F1 hybrids of Lewis and Brown Norway (BN) into sublethally irradiated Brown Norway rats (LBN/F1-->BN), followed by adoptive transfer of S-antigen-specific T cells obtained from Lewis rats; the second produced by transplanting bone marrow cells from BN rats into sublethally irradiated F1 hybrids (BN-->LBN/F1), followed by adoptive transfer of S-antigen-specific T cells obtained from F1 hybrids. As controls, Lewis, F1 hybrids and BN rats also received adoptive transfer of syngeneic uveitogenic T cell lines. All animals were killed on the seventh day after adoptive transfer and their eyes and pineal glands were analysed immunohistochemically, utilizing antibody directed against Lewis specific MHC class II molecules(OX-3). The analyses revealed the development of uveoretinitis and pinealitis in both types of chimeras and in the Lewis and F1 hybrid rats. BN rats did not develop uveoretinitis. OX-3-positive cells were found in the retina and the pineal glands of both types of chimeras, and in the Lewis and F1 hybrid rats but not in the BN rats. These cells in the retina expressed dendritic morphology and perivascular distribution. Retinal pigment epithelia, Müller cells and the vascular endothelia of both chimeras, the two strains, and the F1 hybrid rats did not demonstrate OX-3-positive staining. These results suggest that the bone marrow-derived cells in the retina and pineal gland may present S-antigen to T cells, initiating the cascade of uveoretinitis and pinealitis.

Role of retinal vascular endothelial cells in development of CMV retinitis.

PURPOSE: Although cytomegalovirus (CMV) retinitis is known to occur in association with retinal microangiopathy in individuals with marked immunodeficiency, glial cells are believed to be the initial target cells in the development of retinitis. Moreover, it has been hypothesized that CMV gains access to the retinal glia because of altered vascular permeability. In an attempt to address the hypothesis, we studied 30 autopsy eyes of AIDS patients with systemic CMV infection, with or without clinically apparent CMV retinitis. METHODS: The autopsy eyes were processed in three ways. First, dual immunohistochemical studies were done by using anti-CMV antibodies for immediate early, early, and late antigens. The retinal cell types infected with the virus were then determined by using anti-GFAP, anti-VonWillebrand's factor, neuronal specific enolase, and leukocyte marker CD68. Second, selected eyes were processed for in situ hybridization with DNA probe specific to CMV. Third, an eye with clinically apparent CMV retinitis was submitted for electron microscopic examination. RESULTS: At the site of retinal necrosis in those eyes with a clinical diagnosis of CMV retinitis, the immunohistochemical, in situ hybridization, and ultrastructural examinations revealed that CMV was present primarily in the Müller cells and in perivascular glial cells. Adjacent to these infected cells, focal areas of positive staining for CMV antigen were seen in the glial cells, neuronal cells, and retinal pigment epithelial cells. At these sites most of the retinal capillaries were devoid of endothelial cells. Few vessels located at the advancing margin of retinal necrosis showed the presence of viral proteins in the endothelial cells. CONCLUSIONS: The present results indicate that retinal vascular endothelial cells could be the initial target in the development of viral retinitis, with subsequent spread of the infection to perivascular glia, Müller cells, and other retinal cells, including the retinal pigment epithelium.