Observation of New Isotopes in the Fragmentation of ^{198}Pt at FRIB

Five previously unknown isotopes (^{182,183}Tm, ^{186,187}Yb, ^{190}Lu) were produced, separated, and identified for the first time at the Facility for Rare Isotope Beams (FRIB) using the Advanced Rare Isotope Separator (ARIS). The new isotopes were formed through the interaction of a ^{198}Pt beam with a carbon target at an energy of 186  MeV/u and with a primary beam power of 1.5 kW. Event-by-event particle identification of A, Z, and q for the reaction products was performed by combining measurements of the energy loss, time of flight, magnetic rigidity Bρ, and total kinetic energy. The ARIS separator has a novel two-stage design with high resolving power to strongly suppress contaminant beams. This successful new isotope search was performed less than one year after FRIB operations began and demonstrates the discovery potential of the facility which will ultimately provide 400 kW of primary beam power.

Discovery of ^{39}Na

The new isotope ^{39}Na, the most neutron-rich sodium nucleus observed so far, was discovered at the RIKEN Nishina Center Radioactive Isotope Beam Factory using the projectile fragmentation of an intense ^{48}Ca beam at 345  MeV/nucleon on a beryllium target. Projectile fragments were separated and identified in flight with the large-acceptance two-stage separator BigRIPS. Nine ^{39}Na events have been unambiguously observed in this work and clearly establish the particle stability of ^{39}Na. Furthermore, the lack of observation of ^{35,36}Ne isotopes in this experiment significantly improves the overall confidence that ^{34}Ne is the neutron dripline nucleus of neon. These results provide new key information to understand nuclear binding and nuclear structure under extremely neutron-rich conditions. The newly established stability of ^{39}Na has a significant impact on nuclear models and theories predicting the neutron dripline and also provides a key to understanding the nuclear shell property of ^{39}Na at the neutron number N=28, which is normally a magic number.

β-Delayed One and Two Neutron Emission Probabilities Southeast of ^{132}Sn and the Odd-Even Systematics in r-Process Nuclide Abundances

The β-delayed one- and two-neutron emission probabilities (P_{1n} and P_{2n}) of 20 neutron-rich nuclei with N≥82 have been measured at the RIBF facility of the RIKEN Nishina Center. P_{1n} of ^{130,131}Ag, ^{133,134}Cd, ^{135,136}In, and ^{138,139}Sn were determined for the first time, and stringent upper limits were placed on P_{2n} for nearly all cases. β-delayed two-neutron emission (β2n) was unambiguously identified in ^{133}Cd and ^{135,136}In, and their P_{2n} were measured. Weak β2n was also detected from ^{137,138}Sn. Our results highlight the effect of the N=82 and Z=50 shell closures on β-delayed neutron emission probability and provide stringent benchmarks for newly developed macroscopic-microscopic and self-consistent global models with the inclusion of a statistical treatment of neutron and γ emission. The impact of our measurements on r-process nucleosynthesis was studied in a neutron star merger scenario. Our P_{1n} and P_{2n} have a direct impact on the odd-even staggering of the final abundance, improving the agreement between calculated and observed Solar System abundances. The odd isotope fraction of Ba in r-process-enhanced (r-II) stars is also better reproduced using our new data.

First Application of Mass Measurements with the Rare-RI Ring Reveals the Solar r-Process Abundance Trend at A=122 and A=123

The Rare-RI Ring (R3) is a recently commissioned cyclotronlike storage ring mass spectrometer dedicated to mass measurements of exotic nuclei far from stability at Radioactive Isotope Beam Factory (RIBF) in RIKEN. The first application of mass measurement using the R3 mass spectrometer at RIBF is reported. Rare isotopes produced at RIBF-^{127}Sn, ^{126}In, ^{125}Cd, ^{124}Ag, ^{123}Pd-were injected in R3. Masses of ^{126}In, ^{125}Cd, and ^{123}Pd were measured whereby the mass uncertainty of ^{123}Pd was improved. This is the first reported measurement with a new storage ring mass spectrometry technique realized at a heavy-ion cyclotron and employing individual injection of the preidentified rare nuclei. The latter is essential for the future mass measurements of the rarest isotopes produced at RIBF. The impact of the new ^{123}Pd result on the solar r-process abundances in a neutron star merger event is investigated by performing reaction network calculations of 20 trajectories with varying electron fraction Y_{e}. It is found that the neutron capture cross section on ^{123}Pd increases by a factor of 2.2 and β-delayed neutron emission probability, P_{1  n}, of ^{123}Rh increases by 14%. The neutron capture cross section on ^{122}Pd decreases by a factor of 2.6 leading to pileup of material at A=122, thus reproducing the trend of the solar r-process abundances. The trend of the two-neutron separation energies (S_{2n}) was investigated for the Pd isotopic chain. The new mass measurement with improved uncertainty excludes large changes of the S_{2n} value at N=77. Such large increase of the S_{2n} values before N=82 was proposed as an alternative to the quenching of the N=82 shell gap to reproduce r-process abundances in the mass region of A=112-124.

Probing the Symmetry Energy with the Spectral Pion Ratio

Many neutron star properties, such as the proton fraction, reflect the symmetry energy contributions to the equation of state that dominate when neutron and proton densities differ strongly. To constrain these contributions at suprasaturation densities, we measure the spectra of charged pions produced by colliding rare isotope tin (Sn) beams with isotopically enriched Sn targets. Using ratios of the charged pion spectra measured at high transverse momenta, we deduce the slope of the symmetry energy to be 42<L<117  MeV. This value is slightly lower but consistent with the L values deduced from a recent measurement of the neutron skin thickness of ^{208}Pb.

Mapping of a New Deformation Region around ^{62}Ti

We performed the first direct mass measurements of neutron-rich scandium, titanium, and vanadium isotopes around the neutron number 40 at the RIKEN RI Beam Factory using the time-of-flight magnetic-rigidity technique. The atomic mass excesses of ^{58-60}Sc, ^{60-62}Ti, and ^{62-64}V were measured for the first time. The experimental results show that the two-neutron separation energies in the vicinity of ^{62}Ti increase compared to neighboring nuclei. This shows that the masses of Ti isotopes near N=40 are affected by the Jahn-Teller effect. Therefore, a development of Jahn-Teller stabilization appears below the Cr isotopes, and the systematics in Sc, Ti, and V isotopes suggest that ^{62}Ti is located close to the peak of the Jahn-Teller effect.

Two-Neutron Halo is Unveiled in ^{29}F

We report the measurement of reaction cross sections (σ_{R}^{ex}) of ^{27,29}F with a carbon target at RIKEN. The unexpectedly large σ_{R}^{ex} and derived matter radius identify ^{29}F as the heaviest two-neutron Borromean halo to date. The halo is attributed to neutrons occupying the 2p_{3/2} orbital, thereby vanishing the shell closure associated with the neutron number N=20. The results are explained by state-of-the-art shell model calculations. Coupled-cluster computations based on effective field theories of the strong nuclear force describe the matter radius of ^{27}F but are challenged for ^{29}F.

g Factor of the ^{99}Zr (7/2^{+}) Isomer: Monopole Evolution in the Shape-Coexisting Region

The gyromagnetic factor of the low-lying E=251.96(9)  keV isomeric state of the nucleus ^{99}Zr was measured using the time-dependent perturbed angular distribution technique. This level is assigned a spin and parity of J^{π}=7/2^{+}, with a half-life of T_{1/2}=336(5)  ns. The isomer was produced and spin aligned via the abrasion-fission of a ^{238}U primary beam at RIKEN RIBF. A magnetic moment |μ|=2.31(14)μ_{N} was deduced showing that this isomer is not single particle in nature. A comparison of the experimental values with interacting boson-fermion model IBFM-1 results shows that this state is strongly mixed with a main νd_{5/2} composition. Furthermore, it was found that monopole single-particle evolution changes significantly with the appearance of collective modes, likely due to type-II shell evolution.

Swelling of Doubly Magic ^{48}Ca Core in Ca Isotopes beyond N=28

Interaction cross sections for ^{42-51}Ca on a carbon target at 280  MeV/nucleon have been measured for the first time. The neutron number dependence of derived root-mean-square matter radii shows a significant increase beyond the neutron magic number N=28. Furthermore, this enhancement of matter radii is much larger than that of the previously measured charge radii, indicating a novel growth in neutron skin thickness. A simple examination based on the Fermi-type distribution, and mean field calculations point out that this anomalous enhancement of the nuclear size beyond N=28 results from an enlargement of the core by a sudden increase in the surface diffuseness of the neutron density distribution, which implies the swelling of the bare ^{48}Ca core in Ca isotopes beyond N=28.

Fragmentation of Single-Particle Strength around the Doubly Magic Nucleus ^{132}Sn and the Position of the 0f_{5/2} Proton-Hole State in ^{131}In

Spectroscopic factors of neutron-hole and proton-hole states in ^{131}Sn and ^{131}In, respectively, were measured using one-nucleon removal reactions from doubly magic ^{132}Sn at relativistic energies. For ^{131}In, a 2910(50)-keV γ ray was observed for the first time and tentatively assigned to a decay from a 5/2^{-} state at 3275(50) keV to the known 1/2^{-} level at 365 keV. The spectroscopic factors determined for this new excited state and three other single-hole states provide first evidence for a strong fragmentation of single-hole strength in ^{131}Sn and ^{131}In. The experimental results are compared to theoretical calculations based on the relativistic particle-vibration coupling model and to experimental information for single-hole states in the stable doubly magic nucleus ^{208}Pb.

Location of the Neutron Dripline at Fluorine and Neon

A search for the heaviest isotopes of fluorine, neon, and sodium was conducted by fragmentation of an intense ^{48}Ca beam at 345  MeV/nucleon with a 20-mm-thick beryllium target and identification of isotopes in the large-acceptance separator BigRIPS at the RIKEN Radioactive Isotope Beam Factory. No events were observed for ^{32,33}F, ^{35,36}Ne, and ^{38}Na and only one event for ^{39}Na after extensive running. Comparison with predicted yields excludes the existence of bound states of these unobserved isotopes with high confidence levels. The present work indicates that ^{31}F and ^{34}Ne are the heaviest bound isotopes of fluorine and neon, respectively. The neutron dripline has thus been experimentally confirmed up to neon for the first time since ^{24}O was confirmed to be the dripline nucleus nearly 20 years ago. These data provide new keys to understanding the nuclear stability at extremely neutron-rich conditions.

Improved Value for the Gamow-Teller Strength of the ^{100}Sn Beta Decay

A record number of ^{100}Sn nuclei was detected and new isotopic species toward the proton dripline were discovered at the RIKEN Nishina Center. Decay spectroscopy was performed with the high-efficiency detector arrays WAS3ABi and EURICA. Both the half-life and the β-decay end point energy of ^{100}Sn were measured more precisely than the literature values. The value and the uncertainty of the resulting strength for the pure 0^{+}→1^{+} Gamow-Teller decay was improved to B_{GT}=4.4_{-0.7}^{+0.9}. A discrimination between different model calculations was possible for the first time, and the level scheme of ^{100}In is investigated further.

Magic Nature of Neutrons in ^{54}Ca: First Mass Measurements of ^{55-57}Ca

We perform the first direct mass measurements of neutron-rich calcium isotopes beyond neutron number 34 at the RIKEN Radioactive Isotope Beam Factory by using the time-of-flight magnetic-rigidity technique. The atomic mass excesses of ^{55-57}Ca are determined for the first time to be -18650(160), -13510(250), and -7370(990)  keV, respectively. We examine the emergence of neutron magicity at N=34 based on the new atomic masses. The new masses provide experimental evidence for the appearance of a sizable energy gap between the neutron 2p_{1/2} and 1f_{5/2} orbitals in ^{54}Ca, comparable to the gap between the neutron 2p_{3/2} and 2p_{1/2} orbitals in ^{52}Ca. For the ^{56}Ca nucleus, an open-shell property in neutrons is suggested.

Discovery of ^{60}Ca and Implications For the Stability of ^{70}Ca

The discovery of the important neutron-rich nucleus _{20}^{60}Ca_{40} and seven others near the limits of nuclear stability is reported from the fragmentation of a 345  MeV/u ^{70}Zn projectile beam on ^{9}Be targets at the radioactive ion-beam factory of the RIKEN Nishina Center. The produced fragments were analyzed and unambiguously identified using the BigRIPS two-stage in-flight separator. The eight new neutron-rich nuclei discovered, ^{47}P, ^{49}S, ^{52}Cl, ^{54}Ar, ^{57}K, ^{59,60}Ca, and ^{62}Sc, are the most neutron-rich isotopes of the respective elements. In addition, one event consistent with ^{59}K was registered. The results are compared with the drip lines predicted by a variety of mass models and it is found that the models in best agreement with the observed limits of existence in the explored region tend to predict the even-mass Ca isotopes to be bound out to at least ^{70}Ca.

Differential Cross Section and Photon-Beam Asymmetry for the γ[over →]p → π^{-}Δ^{++}(1232) Reaction at Forward π^{-} Angles for E_{γ}=1.5-2.95 GeV

Differential cross sections and photon-beam asymmetries for the γ[over →]p→π^{-}Δ^{++}(1232) reaction have been measured for 0.7<cosθ_{π}^{c.m.}<1 and E_{γ}=1.5-2.95  GeV at SPring-8/LEPS. The first-ever high statistics cross-section data are obtained in this kinematical region, and the asymmetry data for 1.5<E_{γ}(GeV)<2.8 are obtained for the first time. This reaction has a unique feature for studying the production mechanisms of a pure uu[over ¯] quark pair in the final state from the proton. Although there is no distinct peak structure in the cross sections, a non-negligible excess over the theoretical predictions is observed at E_{γ}=1.5-1.8  GeV. The asymmetries are found to be negative in most of the present kinematical regions, suggesting the dominance of π exchange in the t channel. The negative asymmetries at forward meson production angles are different from the asymmetries previously measured for the photoproduction reactions producing a dd[over ¯] or an ss[over ¯] quark pair in the final state. Advanced theoretical models introducing nucleon resonances and additional unnatural-parity exchanges are needed to reproduce the present data.

Discovery of ^{72}Rb: A Nuclear Sandbank Beyond the Proton Drip Line

In this Letter, the observation of two previously unknown isotopes is presented for the first time: ^{72}Rb with 14 observed events and ^{77}Zr with one observed event. From the nonobservation of the less proton-rich nucleus ^{73}Rb, we derive an upper limit for the ground-state half-life of 81 ns, consistent with the previous upper limit of 30 ns. For ^{72}Rb, we have measured a half-life of 103(22) ns. This observation of a relatively long-lived odd-odd nucleus, ^{72}Rb, with a less exotic odd-even neighbor, ^{73}Rb, being unbound shows the diffuseness of the proton drip line and the possibility of sandbanks to exist beyond it. The ^{72}Rb half-life is consistent with a 5^{+}→5/2^{-} proton decay with an energy of 800-900 keV, in agreement with the atomic mass evaluation proton-separation energy as well as results from the finite-range droplet model and shell model calculations using the GXPF1A interaction. However, we cannot explicitly exclude the possibility of a proton transition between 9^{+}(^{72}Rb)→9/2^{+}(^{71}Kr) isomeric states with a broken mirror symmetry. These results imply that ^{72}Kr is a strong waiting point in x-ray burst rp-process scenarios.

Two-Proton Radioactivity of ^{67}Kr

In an experiment with the BigRIPS separator at the RIKEN Nishina Center, we observed two-proton (2p) emission from ^{67}Kr. At the same time, no evidence for 2p emission of ^{59}Ge and ^{63}Se, two other potential candidates for this exotic radioactivity, could be observed. This observation is in line with Q value predictions which pointed to ^{67}Kr as being the best new candidate among the three for two-proton radioactivity. ^{67}Kr is only the fourth 2p ground-state emitter to be observed with a half-life of the order of a few milliseconds. The decay energy was determined to be 1690(17) keV, the 2p emission branching ratio is 37(14)%, and the half-life of ^{67}Kr is 7.4(30) ms.

Interference Effect between ϕ and Λ(1520) Production Channels in the γp→K^{+}K^{-}p Reaction near Threshold

The ϕ-Λ(1520) interference effect in the γp→K^{+}K^{-}p reaction has been measured for the first time in the energy range from 1.673 to 2.173 GeV. The relative phases between ϕ and Λ(1520) production amplitudes were obtained in the kinematic region where the two resonances overlap. The measurement results support strong constructive interference when K^{+}K^{-} pairs are observed at forward angles but destructive interference for proton emission at forward angles. Furthermore, the observed interference effect does not account for the sqrt[s]=2.1  GeV bump structure in forward differential cross sections for ϕ photoproduction. This fact suggests possible exotic structures such as a hidden-strangeness pentaquark state, a new Pomeron exchange, or rescattering processes via other hyperon states.

New Isotopes and Proton Emitters-Crossing the Drip Line in the Vicinity of ^{100}Sn

Several new isotopes, ^{96}In, ^{94}Cd, ^{92}Ag, and ^{90}Pd, have been identified at the RIKEN Nishina Center. The study of proton drip-line nuclei in the vicinity of ^{100}Sn led to the discovery of new proton emitters ^{93}Ag and ^{89}Rh with half-lives in the submicrosecond range. The systematics of the half-lives of odd-Z nuclei with T_{z}=-1/2 toward ^{99}Sn shows a stabilizing effect of the Z=50 shell closure. Production cross sections for nuclei in the vicinity of ^{100}Sn measured at different energies and target thicknesses were compared to the cross sections calculated by epax taking into account contributions of secondary reactions in the primary target.

Toxin-induced necroptosis is a major mechanism of Staphylococcus aureus lung damage

Staphylococcus aureus USA300 strains cause a highly inflammatory necrotizing pneumonia. The virulence of this strain has been attributed to its expression of multiple toxins that have diverse targets including ADAM10, NLRP3 and CD11b. We demonstrate that induction of necroptosis through RIP1/RIP3/MLKL signaling is a major consequence of S. aureus toxin production. Cytotoxicity could be prevented by inhibiting either RIP1 or MLKL signaling and S. aureus mutants lacking agr, hla or Hla pore formation, lukAB or psms were deficient in inducing cell death in human and murine immune cells. Toxin-associated pore formation was essential, as cell death was blocked by exogenous K+ or dextran. MLKL inhibition also blocked caspase-1 and IL-1β production, suggesting a link to the inflammasome. Rip3^-/- mice exhibited significantly improved staphylococcal clearance and retained an alveolar macrophage population with CD200R and CD206 markers in the setting of acute infection, suggesting increased susceptibility of these leukocytes to necroptosis. The importance of this anti-inflammatory signaling was indicated by the correlation between improved outcome and significantly decreased expression of KC, IL-6, TNF, IL-1α and IL-1β in infected mice. These findings indicate that toxin-induced necroptosis is a major cause of lung pathology in S. aureus pneumonia and suggest the possibility of targeting components of this signaling pathway as a therapeutic strategy.

Staphylococcus aureus (SA) cause a highly inflammatory pneumonia associated with substantial morbidity and mortality. Much of this lung destruction is attributed to toxins that target specific receptors on human and murine cells. We demonstrate that the α-hemolysin (Hla) and other agr-regulated toxins activate RIP1/RIP3/MLKL-mediated necroptosis and IL-1β expression, through a mechanism that involves MLKL pore-formation and inflammasome activation. Cell death can be inhibited by osmoprotectants and K⁺ repletion. Necroptosis results in alveolar macrophage depletion and loss of anti-inflammatory signaling. Rip3^-/- mice maintain significantly greater numbers of alveolar macrophages with anti-inflammatory phenotypes, CD206⁺ and CD200R⁺; decreased proinflammatory cytokine production; and improved SA clearance. Necroptosis represents a common mechanism of pulmonary damage activated by multiple SA toxins.

Spin-density matrix elements for γp→K*0Σ+ at Eγ=1.85-3.0 GeV with evidence for the κ(800) meson exchange

The exclusive reaction γp→K(+)π(-)Σ(+) was measured for the first time using linearly polarized photons at beam energies from 1.85 to 2.96 GeV. Angular distributions in the rest frame of the K(+)π(-) system were fitted to extract spin-density matrix elements of the K(*0) decay. The measured parity spin asymmetry shows that natural-parity exchange is dominant in this reaction. This result clearly indicates the need for t-channel exchange of the κ(800) scalar meson.

Staphylococcus aureus protein A mediates invasion across airway epithelial cells through activation of RhoA GTPase signaling and proteolytic activity

Staphyococcus aureus and especially the epidemic methicillin-resistant S. aureus strains cause severe necrotizing pneumonia. The mechanisms whereby these organisms invade across the mucosal epithelial barrier to initiate invasive infection are not well understood. Protein A (SpA), a highly conserved and abundant surface protein of S. aureus, activates TNF receptor 1 and EGF receptor (EGFR) signaling cascades that can perturb the cytoskeleton. We demonstrate that wild-type S. aureus, but not spa mutants, invade across polarized airway epithelial cell monolayers via the paracellular junctions. SpA stimulated a RhoA/ROCK/MLC cascade, resulting in the contraction of the cytoskeleton. SpA(+) but not SpA(-) mutants stimulated activation of EGFR and along with subsequent calpain activity cleaved the membrane-spanning junctional proteins occludin and E-cadherin, facilitating staphylococcal transmigration through the cell-cell junctions. Treatment of polarized human airway epithelial monolayers with inhibitors of ROCK, EGFR, MAPKs, or calpain prevented staphylococcal penetration through the monolayers. In vivo, blocking calpain activity impeded bacterial invasion into the lung parenchyma. Thus, S. aureus exploits multiple receptors available on the airway mucosal surface to facilitate invasion across epithelial barriers.

Near-threshold Lambda(1520) production by the gamma(p)-->K{+}Lambda(1520) reaction at forward K+ angles

Differential cross sections and photon-beam asymmetries for the gamma(p)-->K{+}Lambda(1520) reaction have been measured with linearly polarized photon beams at energies from the threshold to 2.4 GeV at 0.6<cos(theta){c.m.}{K}<1. A new bump structure was found at W approximately 2.11 GeV in the cross sections. The bump is not well reproduced by theoretical calculations introducing a nucleon resonance with J<or=3/2. This result suggests that the bump might be produced by a nucleon resonance possibly with J>or=5/2 or by a new reaction process, for example, an interference effect with the phi photoproduction having a similar bump structure in the cross sections.

Phosphodiesterase inhibition by naloxone augments the inotropic actions of beta-adrenergic stimulation

BACKGROUND

In a shock state, naloxone generates the cardiovascular pressor effect by displacing the endogenous opiate-like peptide beta-endorphin, resulting in restoration of the normal response to catecholamines. In addition to this opioid antagonistic effect, the non-opiate receptor-mediated effect has also been proposed. The aim of this study was to define the mechanism of non-opiate receptor-mediated action of naloxone.

METHODS

In guinea-pig ventricular tissues, cumulative concentration-response curves for isoproterenol as well as for forskolin and 3-isobutylmethylxanthine (IBMX) were obtained by increasing the concentration stepwise. To assess the effect on the phosphodiesterase (PDE), the effects of naloxone on contractile forces induced by isoproterenol (0.05 microM) in the presence of IBMX, cilostamide (a PDE III inhibitor), or rolipram (a PDE IV inhibitor) were observed. Naloxone-induced changes in cAMP production by isoproterenol both in the absence and in the presence of IBMX were measured. Naloxone-induced changes in cAMP production by forskolin in the presence of IBMX were also measured.

RESULTS

Naloxone (30 microM) produced a leftward shift of the isoproterenol concentration-response curve (0.01-2 microM) without changing the maximal response. Forskolin (0.5-10 microM) produced a concentration-dependent increase in contractile forces. Naloxone increased the maximal inotropic response of forskolin. Naloxone showed no effect on the IBMX concentration-response curve. In the presence of IBMX (200 microM), naloxone did not alter the contractions evoked by isoproterenol or forskolin. Whereas naloxone increased contractile forces significantly (approximately 25%) more than that of isoproterenol in the presence of rolipram, no alteration of contractile forces in the cilostamide-incubated muscles was observed. Naloxone caused a concentration-related increase of cAMP in the absence of IBMX, but caused no change in its presence.

CONCLUSIONS

The enhancement of myocardial contractility by naloxone in the presence of stimulation of adenylyl cyclase activity appears to be mediated by inhibition of PDE, specifically PDE III.

Near-threshold photoproduction of Lambda(1520) from protons and deuterons

Photoproduction of Lambda(1520) with liquid hydrogen and deuterium targets was examined at photon energies below 2.4 GeV in the SPring-8 LEPS experiment. For the first time, the differential cross sections were measured at low energies and with a deuterium target. A large asymmetry of the production cross sections from protons and neutrons was observed at backward K+/0 angles. This suggests the importance of the contact term, which coexists with t-channel K exchange under gauge invariance. This interpretation was compatible with the differential cross sections, decay asymmetry, and photon beam asymmetry measured in the production from protons at forward K+ angles.

Cross sections and beam asymmetry for K;{+}Sigma;{*-} photoproduction from the deuteron at E_{gamma}=1.5-2.4 GeV

The Sigma(1385) resonance, or Sigma;{*}, is well known as part of the standard baryon decuplet with spin J=3/2. Measurements of the reaction gammap-->K;{+}Sigma;{*0} are difficult to extract due to overlap with the nearby Lambda(1405) resonance. However, the reaction gamman-->K;{+}Sigma;{*-} has no overlap with the Lambda(1405) due to its charge. Here we report the first measurement of cross sections and beam asymmetries for photoproduction of the Sigma;{*-} from a deuteron target. The cross sections at forward angles range from 0.4 to 1.2 mub, with a broad maximum near E_{gamma} approximately 1.8 GeV. The beam asymmetries are negative, in contrast with positive values for the gamman-->K;{+}Sigma;{-} reaction.

Differential cross section and photon-beam asymmetry for the gamma n --> K+ Sigma- reaction at E gamma = 1.5-2.4 GeV

Differential cross sections and photon-beam asymmetries have been measured for the gamma n --> K+ Sigma- and gamma p --> K+Sigma0 reactions separately using liquid deuterium and hydrogen targets with incident linearly polarized photon beams of E gamma = 1.5-2.4 GeV at 0.6 < cos ThetacmK< 1. The cross section ratio of sigma K+ Sigma-/sigma K+ Sigma0, expected to be 2 on the basis of the isospin 1/2 exchange, is found to be close to 1. For the K+ Sigma- reaction, large positive asymmetries are observed, indicating the dominance of K* exchange. The large difference between the asymmetries for the K+ Sigma- and K+ Sigma0 reactions cannot be explained by simple theoretical considerations based on Regge model calculations.

Differences in Diagnosis and Treatment Using Telemedicine Versus In-Person Evaluation of Acute Illness

OBJECTIVE

We designed a telemedicine model for diagnosis of common, acute illness to compare telemedicine and in-person evaluations on reproducibility of diagnosis and treatment.

METHODS

Subjects were seen by usual physicians in ambulatory settings. Subjects were also evaluated separately by experienced general pediatricians (study physicians), either in person or via telemedicine, based on random assignment. The primary measure of reproducibility was study physician agreement with usual physician on primary diagnosis. Analysis compared reproducibility for telemedicine versus in-person evaluations. Relevance of agreement on primary diagnosis was measured by comparing agreement on prescribed medications.

RESULTS

Agreement on diagnosis of study physicians with usual physicians for the 492 visits studied was 89%. The difference in the proportion of visits with disagreements between telemedicine study and in-person study evaluations (13.8% vs 8.3%, respectively) bordered on significance (P = .051). Disagreement proportions for prescriptions were similar (32.2% vs 27.4%), however. Telemedicine evaluation for children with upper respiratory tract (URI)-ear symptoms involved unique technical requirements and clinical judgments. For this largest subgroup of 202 visits, disagreement on diagnosis for telemedicine occurred more often than for in-person evaluation (17.6 vs 6.3%, P < .02). For the remaining 290 visits, telemedicine and in-person study physicians disagreed on diagnosis about equally (11.5 vs 9.9%).

CONCLUSIONS

Excluding the URI-ear group, reproducibility of telemedicine diagnosis did not differ from that of in-person diagnosis. For the URI-ear group, reproducibility of diagnosis by telemedicine and in-person evaluation varied significantly.

Effectiveness of Telemedicine in Replacing In-Person Evaluation for Acute Childhood Illness in Office Settings

For the purpose of reducing the social and economic burden imposed by common acute childhood illness, we developed a telemedicine model to enable diagnosis and treatment of illness episodes presenting in pediatric office settings. The study objective was to assess the effectiveness of this telemedicine model in replacing illness visits to traditional healthcare settings and to compare effectiveness of this model (base model) with that of alternative models including simple office laboratory tests and albuterol administration (simple model) or a complete complement of tests and procedures (extended model). Eligible subjects had an acute problem and were seen in the pediatric primary care practice or pediatric emergency department of the University of Rochester Medical Center. All subjects were seen by the setting's usual physician. Subjects were also evaluated, based on random assignment, by a study physician in person or by a study physician via telemedicine. Effectiveness was defined as completion of the visit to the point that diagnosis was made. Forms completed by study physicians, and standard medical records indicating the tests and procedures requested for the purpose of completing the visit, were used to identify the model used in completing the visit. Effectiveness (proportion of visits completed) of the base model was assessed and its effectiveness was compared to that of simple and extended telemedicine models. Among 520 randomized visits, 492 were evaluated by study physicians in person (253) or via telemedicine (239). Using the base model, study physicians completed 74.1% of visits via telemedicine compared to 76.7% for study physicians in person and 76.0% for usual physicians. The simple model increased completion rates substantially. Using this model, study physicians completed 84.9% of visits via telemedicine compared to 86.6% for study physicians in person and 85.2% for usual physicians. The extended model increased effectiveness in completing visits still more, with telemedicine study physicians completing 97.1% of visits compared to 96.8% for in-person study physicians and 100% for usual physicians. Approximately 85% of illness visits presenting to primary care pediatric practice could be completed using a telemedicine model that included only simple office laboratory testing and albuterol administration.

Near-threshold diffractive psi-meson photoproduction from the proton

Photoproduction of a phi meson on protons was studied by means of linearly polarized photons at forward angles in the low-energy region from threshold to Egamma = 2.37 GeV. The differential cross sections at t = -|t|min do not increase smoothly as Egamma increases but show a local maximum at around 2.0 GeV. The angular distributions demonstrate that phi mesons are photoproduced predominantly by helicity-conserving processes, and the local maximum is not likely due to unnatural-parity processes.

Comparison of evidence-based therapeutic intervention between community- and hospital-based primary care clinics

The purpose of this study was to compare the proportion of therapeutic interventions that is supported by scientific evidence between hospital-based and community-based primary care clinics. The study setting is a primary care clinic in university-affiliated tertiary hospital and community-based primary care clinic in a region in Seoul. A retrospective review of patients' medical records was done according to the primary diagnosis and treatment for 890 patients in community-based clinic and 307 in hospital-based clinic. The evidence for the intervention was searched for in Medline (1966-2001) and other evidence-based databases. The evidence was then classified as one of the three categories (i) evidence from randomised controlled trials (RCTs); (ii) convincing non-experimental evidence; and (iii) interventions without substantial evidence. In the hospital-based clinics, out of 356 primary diagnosis and treatment pairs, 59.6% were supported by evidence from at least one RCTs, and 19.4% were supported by convincing non-experimental evidence. In the community-based clinics, 47.1% out of 893 pairs and 10.5% fell into each category. As a result, the proportion of interventions in community settings that were based on evidence meeting our criteria was significantly lower than that of the hospital-based settings. To facilitate evidence-based practice, supportive activity should be focused on the primary care settings based on community where medical practices are less evidence-based.

Beam-polarization asymmetries for the p(gamma-->, K+)Lambda and p(gamma-->, K+)Sigma(0) reactions for E(gamma)=1.5-2.4 GeV

Beam polarization asymmetries for the p(gamma-->,K+)Lambda and p(gamma-->,K+)Sigma(0) reactions are measured for the first time for E(gamma)=1.5-2.4 GeV and 0.6<cos((theta(c.m.)(K+))<1.0 by using linearly polarized photons at the Laser-Electron-Photon facility at SPring-8 (LEPS). The observed asymmetries are positive and gradually increase with rising photon energy. The data are not consistent with theoretical predictions based on tree-level effective-Lagrangian approaches. Including the new results in the development of the models is, therefore, crucial for understanding the reaction mechanism and to test the presence of baryon resonances which are predicted in quark models but are thus far undiscovered.

Evidence for a narrow S = +1 baryon resonance in photoproduction from the neutron

The gamman-->K(+)K(-)n reaction on 12C has been studied by measuring both K+ and K- at forward angles. A sharp baryon resonance peak was observed at 1.54+/-0.01 GeV/c(2) with a width smaller than 25 MeV/c(2) and a Gaussian significance of 4.6sigma. The strangeness quantum number (S) of the baryon resonance is +1. It can be interpreted as a molecular meson-baryon resonance or alternatively as an exotic five-quark state (uuddsmacr;) that decays into a K+ and a neutron. The resonance is consistent with the lowest member of an antidecuplet of baryons predicted by the chiral soliton model.

Primary antiphospholipid syndrome presenting with abdominal angina and splenic infarction

The antiphospholipid syndrome is an autoimmune hypercoagulability syndrome in which a wide variety of thromboembolic diseases may occur. Gastrointestinal manifestations associated with vascular occlusion include Budd-Chiari syndrome, hepatic and splenic infarction, pancreatitis, omental and intestinal infarction, and esophageal variceal bleeding due to portal vein thrombosis, but chronic mesenteric ischemia associated with mesenteric arterial thrombosis is very rare in this syndrome. We experienced a female patient with primary antiphospholipid syndrome with abdominal angina and splenic infarction associated with celiac trunk and mesenteric arterial thromboses. This is the first report describing chronic mesenteric ischemia and splenic infarction in a patient with primary antiphospholipid syndrome.

Efficacy of low-dose clarithromycin triple therapy and tinidazole-containing triple therapy for Helicobacter pylori eradication

BACKGROUND

Proton pump inhibitor-based triple therapies are recommended as the first-line treatment for Helicobacter pylori eradication.

AIM

To evaluate the efficacies of low-dose clarithromycin triple therapy and tinidazole-containing triple therapy in a metronidazole resistance prevalent area and to compare the efficacies with standard triple therapy.

METHODS

In a randomized, multicentre, prospective study, a total of 352 patients with duodenal ulcer or non-ulcer dyspepsia were randomly divided into three groups according to the administered regimen: OAC250 group (omeprazole, 20 mg, amoxicillin, 1000 mg, and clarithromycin, 250 mg), OAC500 group (omeprazole, 20 mg, amoxicillin, 1000 mg, and clarithromycin, 500 mg) and OTC group (omeprazole, 20 mg, tinidazole, 500 mg, and clarithromycin, 500 mg). The three groups received each regimen twice daily for 7 days. Upper gastrointestinal endoscopy was performed before and 4 weeks after treatment. H. pylori status was determined by rapid urease test and 13C urea breath test.

RESULTS

The eradication rates in the OAC250, OAC500 and OTC groups were 76.2%, 65.7% and 64.8% (95% confidence interval: 67.9-84.4%, 56.7-74.8% and 55.7-73.9%), respectively, by intention-to-treat analysis (P=0.149) and 92.8%, 87.2% and 84.1% (95% confidence interval: 84.4-97.3%, 77.9-93.8% and 73.9-91.2%), respectively, by per protocol analysis (P=0.088). All regimens were well tolerated and compliance was excellent.

CONCLUSIONS

Both low-dose clarithromycin triple therapy and tinidazole-containing triple therapy are effective and safe regimens for H. pylori eradication.

Tissue paper for hemostasis of spot dermabrasion

Dermabrasion remains one of the effective ways to treat scars and facial wrinkles. Spot dermabrasion is for a localized limited area. Bleeding and oozing from the abraded wound are cumbersome during the operation. Small pieces of tissue paper were used for the intraoperative hemostasis. The efficiency and safety of the tissue paper as a temporary dressing for hemostasis was discussed and presented. It is simple, cost-effective, and easy to use for hemostasis from spot dermabrasion.

The outcome of the nonoperated contralateral hand in carpal tunnel syndrome

It is not well known how the nonoperated contralateral hand behaves in bilateral carpal tunnel syndrome (CTS). The postoperative clinical course of the nonoperated contralateral hand in unilateral CTS is not well documented either. Of 324 CTS patients, the authors studied 37 who had carpal tunnel release on one hand only to evaluate the postoperative outcome of the nonoperated contralateral hand. The other 287 patients had operations on both hands. Seven patients were excluded because of missing data or because they could not be contacted. All 324 patients were subject to clinical and electrodiagnostic studies on both hands. The patients were divided into three groups. Group I was composed of patients who had bilateral CTS, diagnosed clinically and electrophysiologically, but who had surgery done only on the hand with the most pronounced symptoms. The patients in group II showed symptoms of CTS in one hand only. However, the opposite hand was diagnosed with subclinical CTS: Electrodiagnostic studies showed involvement of the median nerve, but without symptoms. Group III was composed of true unilateral CTS patients, diagnosed by symptoms and electrodiagnostic study. The results of the electrodiagnosis were categorized according to the severity of median nerve damage (mild, moderate, severe). The outcome and postoperative clinical course of the nonoperated contralateral hand were evaluated by electromyography and telephone survey. This method of survey was used because of the vast spread of patients throughout the country. Within 1 year, all 30 operated hands showed significant improvement, 20 of which belonged to group I. Regarding progress of the nonoperated contralateral hand, 10 patients showed improvement of one grade whereas 5 patients showed three grades of improvement. In another 5 patients there was no change whatsoever. In addition, from groups II and III there were 5 patients who showed no change in the nonoperated hand. The postoperative electromyographic findings of the nonoperated contralateral hand was not commensurate with the symptoms. However, regardless of electromyographic results, the nonoperated contralateral hand showed significant improvement (p < 0.0001). Patients with unilateral CTS did not experience any symptom development in the nonoperated contralateral hand.

Hand elevation: a new test for carpal tunnel syndrome

Hand elevation can reproduce the symptoms of carpal tunnel syndrome. This phenomenon prompted the idea of developing a simple hand elevation test to diagnose carpal tunnel syndrome. A total of 200 hands in 118 patients diagnosed with carpal tunnel syndrome were tested prospectively from September 6, 1999, to February 3, 2000. Three provocative tests (hand elevation test, Phalen's test, and Tinel's test) were performed on each hand for both the experimental group (200 hands) and the control group (200 hands). McNemar chi-squared analysis was used to compare the sensitivity and specificity of the new hand elevation test with those of Phalen's test and Tinel's test. The sensitivity and specificity of the hand elevation test is 75.5% and 98.5% respectively. Phalen's test had 67.5% sensitivity and 91.0% specificity. Tinel's test had 67.5% sensitivity and 90.0% specificity. The difference in sensitivities between the hand elevation test and Phalen's test was significant (p = 0.05). No significant difference was found in the sensitivity between the hand elevation test and Tinel's test. The comparison of specificity of the hand elevation test and Phalen's test was significant (p = 0.001). Significance was also observed in specificity between the hand elevation test and Tinel's test (p = 0.001). In this study, the sensitivity and specificity of the elevation test were higher than those of Phalen's test and Tinel's test. Statistical analysis confirms the eligibility of the hand elevation test as a useful, provocative test.

Laser punch-out for acne scars

Patients with acne scars want smooth facial skin. However, achieving this is difficult with dermabrasion or chemical peeling. Nor can acne scars be covered with cosmetics, due to their ice-picked or cobblestone appearance. Laser resurfacing is more effective and safer than other conventional methods due to its precision with depth control and variable methods of surface cutting. Even depth resurfacing with a laser shows unsatisfactory results, therefore, for the deep-sited acne scar the cutting methods have to be changed according to the depth and pattern of the scar. For 2 years, starting in January 1996, we treated 71 patients with a high-powered CO2 laser (Ultrapulse). Different resurfacing methods were applied according to the depth and pattern of the scars. For mild depressed scars, even depth resurfacing was done. For moderate-depth acne scars, the shoulder technique was also used. For the deepest and ice-picked scars, the laser punch-out was combined. Laser resurfacing was carried out at 300-500 mJ, with two to five passes. Laser punch-out was done at 500 mJ, with three to seven continuous passes on the ice-picked scar. From the pathologic findings of acne scars showing that there was thick intradermal scar, we knew that laser punch-out was necessary for improvement of acne scars. Depth-wide, the ice-picked scars improved by over 80% and the sharp demarcated margin of the acne scar faded out. Most of the patients with acne scars were satisfied with laser resurfacing. Only six patients had a second laser treatment, with an interval of 12 months. There were no hypertrophic scars after laser resurfacing, but erythema lasted for 3-12 months. Patients taking oral retinoic acid were not contraindicated for laser resurfacing but required special caution because they had atrophic skin and delayed wound healing. Laser resurfacing is the most versatile method for acne scars, with a high-powered CO2 laser. The laser punch-out method is better than even depth resurfacing for improving deep acne scars and can be combined with the shoulder technique or even depth resurfacing according to the type of acne scar.

Sulfhydryl modification affects coronary artery tension by changing activity of delayed rectifier K+ current

It has been reported that a change in the cellular redox state may be involved in the regulation of vascular tone, but the underlying mechanism is not fully understood. The present study was designed to investigate the cellular effect of sulfhydryl modifying agents in the coronary artery of rabbit using the tension measurement and whole cell clamping method. The application of diamide, a sulfhydryl oxidizing agent, relaxed the endothelium denuded coronary arteries in a dose dependent manner. The fact that this diamide-induced relaxation was significantly attenuated by a pretreatment of 4-AP, and the coronary arteries precontracted with 100 mM K+ instead of histamine, suggests the involvement of 4-AP sensitive K+ channels in the diamide-induced relaxation of coronary arteries. Whole cell patch clamp studies revealed that the 4-AP sensitive IdK was significantly enhanced by the membrane permeant oxidizing agents, diamide and DTDP, and were reversed by subsequent exposure to the reducing agent, DTT. Neither the membrane impermeant oxidizing or reducing agents, GSSG or GSH, had any effect on the activity of IdK, indicating that intracellular sulfhydryl modification is critical for modulating IdK activity. The Diamide failed to significantly alter the voltage dependence of the activation and inactivation parameters, and did not change the inactivation process, suggesting that diamide increases the number of functional channels without altering their gating properties. Since IdK has been believed to play an important role in regulating membrane potential and arterial tone, our results about the effect of sulfhydryl modifying agents on coronary arterial tone and IdK activity should help understand the pathophysiology of the diseases, where oxidative damage has been implicated.

Membrane stretch increases the activity of Ca(2+)-activated K+ channels in rabbit coronary vascular smooth muscles

It has been proposed that Ca(2+)-activated K+ channels play an essential role in maintaining vascular tone during stretch of blood vessel. However, the underlying mechanism of stretch-induced change of Ca(2+)-activated K+ channel activities are still unknown. The present experiment was designed to investigate the effect of membrane stretch on these channels whose activity was measured from rabbit coronary smooth muscle cells using a patch clamp technique. Ca(2+)-activated K+ channel were identified by their Ca2+ and voltage dependencies and its large conductances as in other preparations. Perfusion of cells with a hypotonic solution, which mimics stretching the cell membrane by making a cell swelling, produced an increase in channel activity in cell-attached patch mode. The similar increase was observed when negative pressure was applied into the patch pipette for stretching the cell membrane within a patch area. In inside-out patch, stretch still increased channel activity even under the conditions which exclude the possible involvement of secondary messengers, or of transmembrane Ca2+ influx via stretch-activated cation channels. Pretreatment of arachidonic acid or albumin showed no effect on stretch-induced channel activation, excluding the possibility of fatty acids mediated channel activation during membrane stretch. These results indicate that the stretch may directly increase the activity of Ca(2+)-activated K+ channels in our experimental condition.

A prospective study of the anatomic variations of the median nerve in the carpal tunnel in Asians

A prospective study of anatomic variations of the median nerve and its relationship to the surrounding structures was performed of 354 consecutive operations in 192 patients with carpal tunnel syndrome at Korea University Anam Hospital from July 1995 to September 1997. A total of 184 patients were women and 8 patients were men. A total of 162 patients were bilateral and 30 were unilateral. Regarding the course of the motor branch, the extraligamentous type was most common (96.1%, 340 patients). A total of 81.1% of patients (N = 287) had the origin of the motor branch at the radial side of the median nerve (or radial one third), and 17.2% of patients (N = 61) had the origin of the motor branch at the anterior portion of the median nerve. Of these 61 patients, 30 patients (49.1%) were of the preligamentous type. Only one motor nerve branch was found in 89.5% of patients (N = 317), and multiple branches were found in 10.5% of patients. As a result of the comparison between two hands when both hands were operated, the origin and number of motor branches and their courses were identical in most patients (>60%). Hypertrophy of the flexor pollicis brevis was found in 8.5% of patients (N = 30), hypertrophy of the palmaris brevis was found in 4.2% of patients (N = 15), absence of the palmaris longus was discovered in 0.6% of patients (N = 2), existence of the median artery was found in 0.6% of patients (N = 2), and high division of the median nerve rejoining with the thenar motor nerve was found in 0.3% of patients (N = 1). Clearly, the anatomy of the carpal tunnel in Koreans is somewhat different, in part, from the results obtained from studies of whites, but overall results are not significantly different. These results can help obtain a better surgical outcome and complete decompression of the median nerve during operation while preventing inappropriate or inadvertent injury to the motor branch of the median nerve in Koreans.

Facial resurfacing in xeroderma pigmentosum with chemical peeling

We describe our experience with two patients with xeroderma pigmentosum who underwent multiple trichloroacetic acid chemical peels. Trichloroacetic acid and phenol were used in one case. Until now numerous treatment modalities have been reported. Deep chemical peeling has not been reported before in patients with xeroderma pigmentosum. Chemical peeling is a simple procedure with less associated morbidity.

Down-regulation of insulin-like growth factor binding proteins and growth modulation in hepatoma cells by retinoic acid

We observed that all-trans-retinoic acid (RA) down-regulated insulin-like growth factor binding proteins (IGFBPs) in cultured human hepatoma cells (Hep 3B, PLC/PRF/5, and Hep G2); therefore, we characterized the role of this down-regulation in cell growth. Treatment with 10 micromol/L RA revealed a rapid decrease in IGFBP-3 within 2 days, and continued treatment with RA for 6 days resulted in a time-dependent stimulation of Hep 3B cell growth. However, RA treatment decreased IGFBP-1 in PLC/PRF/5 cells and in Hep G2 cells, and the growth-stimulatory activity of RA was transient and less prominent, and was finally obliterated in both cell lines. The addition of 5 ng/mL or 50 ng/mL insulin-like growth factors (IGFs) did not change the growth effects elicited by RA. The addition of IGFBP-3 (1,000 ng/mL) inhibited the growth of Hep 3B cells and counteracted the growth-stimulatory activity of RA, but not completely, suggesting that RA has direct growth-stimulatory activity and that this is enhanced by autocrine down-regulation of IGFBP-3. IGFBP-3 also inhibited the growth of PLC/PRF/5 cells and of Hep G2 cells. Treatment with phosphorylated IGFBP-1 (1,000 ng/mL) alone or with RA did not affect the growth of PLC/PRF/5 cells or Hep G2 cells. However, addition of dephosphorylated IGFBP-1, derived from in vivo dephosphorylation of the phosphorylated form, stimulated the growth of both cell lines, independent of interaction with IGF-I. From these observations, we propose that RA down-regulates IGFBPs, which in turn causes autocrine modulation of cell growth independent of IGF in hepatoma cells in vitro or in vivo. In addition, RA regulates IGFBPs at the posttranscriptional (Hep 3B cells and Hep G2 cells) or transcriptional level (PLC/PRF/5 cells) in a cell-specific manner.

Report of phenol peel for Asians

With the advancement of trichloroacetic acid peel technology and wound care, trichloroacetic acid peeling has become very successful in Korea. Its success has opened studies on the possibility of using phenol on Korean skin. Dr. Mee's phenol formula (molding mask technique) was chosen for experiments on Korean skin because of the presumed safety of use on non-Caucasian skin. Between January of 1996 and January of 1998, 30 cases of significant small pox scars were treated with phenol at the Korea University Anam Hospital. The age range was from 43 to 60 years, with a mean of 49 years. The average follow-up period was 13 months, ranging from 1 month to 2 years. All of the procedures were performed in the operating room while the patient was under deep i.v. sedation. After the entire face was peeled, it was covered with an occlusive tape mask. During the recovery period, the patients underwent a post-peel skin care program. All 30 patients showed significant improvement of the severe pox marks with a marked rejuvenation effect. There was no sign of hypopigmentation or hyperpigmentation. As a complication, two patients developed hypertrophic scars on the perioral area, which responded well to steroid injections. Another pair of patients had herpetic infection, which left minimal scarring. Five patients developed cardiac arrhythmia with this rapid technique, but this was safely managed by an anesthesiologist during the procedure. Korean skin belongs to Fitzpatrick types IV and V and occasionally to type III or VI. It is common knowledge that performing chemical peeling on the latter types of skin is dangerous, but in this report, excellent results were obtained from all 30 patients, even though the peeling itself was very deep. With more knowledge and experience, phenol peel can be safely conducted on Asian skin.

Correlation of clinical history and electrodiagnostic abnormalities with outcome after surgery for carpal tunnel syndrome

A retrospective study on 294 wrists in 154 patients who had been diagnosed with carpal tunnel syndrome and subsequently had surgery performed was undertaken; both clinical and electrodiagnostic findings were correlated. The cases were divided into three groups based on electromyographic severity (mild, moderate, severe), and recovery from symptoms was evaluated after 1 week, 3 months, and 1 year. The cases were also divided into five groups based on symptom duration, and the same investigations were performed. All operations were conducted by applying the open release method with the limited-palmar incision technique. Operative outcomes showed no association between recovery from symptoms and the severity of electromyographic findings or the duration of symptoms, although the group that had the shortest duration of symptoms recovered faster than the long-duration groups statistically. Postoperative results after 1 year were also successful for those patients who had had symptoms of long duration. Of the 294 wrist operations studied, good to excellent postoperative outcomes were recorded in 242 cases (82 percent), fair outcomes in 39 cases (13 percent), and poor outcomes in 13 cases (4 percent). Patients whose electromyogram revealed double crush syndrome still showed improvement, with good-to-excellent results in 11 out of 15 cases (73 percent). Patients with diabetes mellitus also showed improvement, with good-to-excellent results in 14 out of 19 patients (74 percent). This study showed that postoperative results were satisfactory within 1 year, regardless of the degree of electromyographic severity, symptom duration, presence of diabetes mellitus, or double crush syndrome.

pH regulation of voltage-dependent K+ channels in canine pulmonary arterial smooth muscle cells

Voltage-dependent K+ currents (Kv) may play a role in hypoxic pulmonary vaso constriction. The effects of changes in extracellular pH (pHo) and intracellular pH (pHi) on Kv currents in smooth muscle cells isolated from canine pulmonary artery were studied using the amphotericin B perforated-patch technique for whole-cell recording. Under these conditions, cellular mechanisms for pHi regulation remain intact, and the effects of pHo were examined by directly changing the pH of external solutions and changes in pHi were produced by external application of weak extracellular acids and bases and the cation/H+ ionophore, nigericin. Ca(2+)-free external solutions were used to isolate whole-cell Kv currents from contaminating Ca(2+)-activated K+ currents. Extracellular acidification (pHo = 6.4-7.0) reduced Kv currents, produced a positive voltage shift in steady-state activation and reduced maximum Kv conductance (gK). Extracellular alkalinization (pHo = 8.0-8.4) increased Kv currents, produced a small negative voltage shift in steady-state activation, and increased gK. Intracellular acidification produced by exposure of cells to external sodium butyrate (20 mM) or nigericin (5 micrograms/ml) increased Kv currents, produced a negative voltage shift in steady-state activation, and increased gK. Intracellular alkalinization produced by exposure of cells to external trimethylamine (20 mM) reduced Kv currents, produced a small positive voltage shift in steady-state activation and reduced gK. These results suggest that the effects of pHo and pHi on Kv currents are distinctly different, but are consistent with reported effects of pHo and pHi on hypoxic pulmonary vasoconstriction, suggesting that such modulation may be mediated in party by pH-induced alterations in Kv channel activity.

Differences in immunophenotyping of mucosal lymphocytes between ulcerative colitis and Crohn's disease

OBJECTIVES

Immunologic studies have characterized the numbers and types of inflammatory cells in diseased inflammatory bowel disease (IBD) mucosa but have yielded conflicting results regarding intestinal lymphocytes activation in IBD. We investigated the levels of lymphocytes subsets, interleukin-2 receptor, transferrin receptor, and T cell receptors in mainly isolated lamina propria lymphocytes. Including intraepithelial lymphocytes of normal colonic mucosa or IBD (ulcerative colitis and Crohn's disease) mucosa to understand the pathogenesis of IBD. We have results from this study.

RESULTS

1) In comparing ulcerative colitis with control, IL-2R (p < 0.05), TR (p < 0.01), and CD3/HLA-DR (< 0.05) showed a significant increase. 2) In comparing Crohn's disease with control, CD3 (P < 0.05), TCR alpha/beta (p < 0.01) and TCR gamma/delta (p < 0.05) showed a significant decrease. 3) In comparing Crohn's disease with ulcerative colitis, CD19 (p < 0.01), TR (p < 0.01), TCR alpha/beta (p < 0.01) and TCR gamma/delta (p < 0.05) showed a significant decrease.

CONCLUSION

From these results, there are increased T cell markers, IL-2R, TR, and CD3/HLA-DR in UC, but differently, decreased CD3, TCR alpha/beta and TCR gamma/delta in CD compared with control. In addition, definitive differences in lymphocytes markers, CD19, TR, TCR alpha/beta and TCR gamma/delta, which are higher in UC than in CD, may elucidate the different immunopathogenesis between UC and CD.

Apoptosis induced by retinoic acid in Hep 3B cells in vitro

Human hepatoma Hep 3B cells underwent apoptosis in response to 100 microM all-trans retinoic acid (RA) in full serum (10% fetal calf serum) condition in vitro. Cell death began approximately 24 h following treatment, with more than 80% of the cells dead after 60 h. The dead cells, mainly detached cells, exhibited condensed chromatin and DNA fragmentation, which are indicative of endonuclease activation and are the hallmarks of apoptosis in epithelial cells. Concurrent exposure to 1 microM cycloheximide (CX) prevented approximately 50% of cell death and DNA fragmentation induced by RA. Thus, other toxic injury to the cells as well as apoptosis might be involved in cell death. Sixty hours exposure of RA decreased the percentage of cells in G1 phase (16.3 +/- 0.4% versus 52.4 +/- 2.1%; P < or = 0.01) and in G2/M phase (13.4 +/- 1.2% versus 21.2 +/- 0.7%; P < or = 0.01), but did not change percent of cells in S phase (20.8 +/- 0.2% versus 20.7 +/- 0.5%) of the cell cycle compared with control. RA may have caused accumulation of Hep 3B cells before G1 phase, and that G0/G1 transition is a main check point in the active process of apoptosis. Electron micrographs of the cells treated with RA revealed typical morphologic changes of apoptosis, besides toxic injury to the cells. These data strongly indicate that RA is able to induce apoptosis and the induction of apoptosis may contribute to the antitumor activity of RA against hepatoma cells.