NKG2D⁺ IFN-γ⁺ CD8⁺ T cells are responsible for palladium allergy

Nickel, cobalt, and chromium are well known to be causal agents of allergic contact dermatitis. Palladium (Pd) can also cause allergic disease and exposure results from wide use of this metal in dental restorations and jewelry. Metal allergy is categorized as a delayed-type hypersensitivity, and metal-responsive T cell clones have been isolated from allergic patients. However, compared to nickel, little is known about the pathology of allergic disease mediated by Pd, and pathogenic T cells are poorly understood. To identify the pathogenic T cells that are responsible for onset of Pd allergy, we enriched metal-responsive lymphocytes by sequential adoptive transfer of involved lymph node cells. Here we show that sequential adoptive transfer gradually increased the incidence and the intensity of Pd allergy, and CD8⁺ T cells are responsible for the disease as CD8⁺ T cell-depleted mice and β2-microglobulin-deficient mice did not develop Pd allergy. In addition, we found that draining lymph node cells skewed toward CD8⁺ T cells in response to Pd challenge in 8th adoptive transferred recipient mice. The CD8⁺ T cells expressed NKG2D, a costimulatory molecule involved in the production of IFN-γ. NKG2D ligand was also induced in Pd-injected tissues. Furthermore, both NKG2D ligand-transgenic mice, where NKG2D is downmodulated, and IFN-γ-deficient mice showed impaired Pd allergy. Taken together, these results indicate that IFN-γ-producing NKG2D⁺ CD8⁺ T cells are responsible for Pd allergy and suggest that NKG2D is a potential therapeutic target for treatment of metal allergy.

Update on anesthetic complications of robotic thoracic surgery

In the last decade, there has been increasing use of the da Vinci® robot surgical system to perform minimally invasive thoracic surgery. The robotic technology can be applied for surgery of the lungs, mediastinum, and esophagus. A number of case reports have been shown steep learning curve, and promising surgical outcome with this new technology. However, anesthesia management of the robotic thoracic surgery can be complex and requires further education. For example, most of the cases require sufficient lung collapse in order to provide adequate surgical field. In addition, a unique operative setting, such as patient positioning and capnothorax can make anesthesia management further challenging. Hence, anesthesiologists should have better awareness of adverse events or complications related to the robotic surgery to accomplish successful anesthesia management. This review will focus on the potential complications of robotic thoracic surgery involving the lungs, mediastinum and esophagus.

Study on different bandages and application techniques for achieving stiffer compression

OBJECTIVES

The objective of this study was to investigate the relationship between interface pressure and stiffness of compression achieved by various combinations of bandages and application techniques.

METHOD

There were eight healthy volunteers. One roll (4.5 m) of four types of bandages with different extensibilities (0, 90, 108 and 218%) was applied to the leg in single-layer bandage fashion with eight random tensions. Then, the leg was wrapped with one to eight rolls in multi-layer bandage fashion.

RESULTS

Each combination of bandage and application technique displayed an indigenous linear interface pressure-static stiffness index relationship. With single-layer bandage, lower extensibility was associated with higher static stiffness index at a given interface pressure. With multi-layer bandage, the static stiffness index at a given interface pressure was independent of the bandage type.

CONCLUSION

The stiffness at a given interface pressure was affected by the extensibility with single-layer bandage but not with multi-layer bandage.

Time-resolved measurement of interatomic coulombic decay in Ne2

The lifetime of interatomic Coulombic decay (ICD) [L. S. Cederbaum et al., Phys. Rev. Lett. 79, 4778 (1997)] in Ne2 is determined via an extreme ultraviolet pump-probe experiment at the Free-Electron Laser in Hamburg. The pump pulse creates a 2s inner-shell vacancy in one of the two Ne atoms, whereupon the ionized dimer undergoes ICD resulting in a repulsive Ne+(2p(-1))-Ne+(2p(-1)) state, which is probed with a second pulse, removing a further electron. The yield of coincident Ne+-Ne2+ pairs is recorded as a function of the pump-probe delay, allowing us to deduce the ICD lifetime of the Ne2(+)(2s(-1)) state to be (150±50)  fs, in agreement with quantum calculations.

Dynamics of hollow atom formation in intense x-ray pulses probed by partial covariance mapping

When exposed to ultraintense x-radiation sources such as free electron lasers (FELs) the innermost electronic shell can efficiently be emptied, creating a transient hollow atom or molecule. Understanding the femtosecond dynamics of such systems is fundamental to achieving atomic resolution in flash diffraction imaging of noncrystallized complex biological samples. We demonstrate the capacity of a correlation method called "partial covariance mapping" to probe the electron dynamics of neon atoms exposed to intense 8 fs pulses of 1062 eV photons. A complete picture of ionization processes competing in hollow atom formation and decay is visualized with unprecedented ease and the map reveals hitherto unobserved nonlinear sequences of photoionization and Auger events. The technique is particularly well suited to the high counting rate inherent in FEL experiments.

Deep inner-shell multiphoton ionization by intense x-ray free-electron laser pulses

We have investigated multiphoton multiple ionization dynamics of xenon atoms using a new x-ray free-electron laser facility, SPring-8 Angstrom Compact free electron LAser (SACLA) in Japan, and identified that Xe(n+) with n up to 26 is produced at a photon energy of 5.5 keV. The observed high charge states (n≥24) are produced via five-photon absorption, evidencing the occurrence of multiphoton absorption involving deep inner shells. A newly developed theoretical model, which shows good agreement with the experiment, elucidates the complex pathways of sequential electronic decay cascades accessible in heavy atoms. The present study of heavy-atom ionization dynamics in high-intensity hard-x-ray pulses makes a step forward towards molecular structure determination with x-ray free-electron lasers.

Ultrafast charge rearrangement and nuclear dynamics upon inner-shell multiple ionization of small polyatomic molecules

Ionization and fragmentation of methylselenol (CH(3)SeH) molecules by intense (>10(17) W/cm(2)) 5 fs x-ray pulses (ħω=2 keV) are studied by coincident ion momentum spectroscopy. We contrast the measured charge state distribution with data on atomic Kr, determine kinetic energies of resulting ionic fragments, and compare them to the outcome of a Coulomb explosion model. We find signatures of ultrafast charge redistribution from the inner-shell ionized Se atom to its molecular partners, and observe significant displacement of the atomic constituents in the course of multiple ionization.

Cholinergic interneurons suppress action potential initiation of medium spiny neurons in rat nucleus accumbens shell

Acetylcholine plays a crucial role in the regulation of neural functions, including dopamine release, synaptic activity, and intrinsic electrophysiological properties of the nucleus accumbens (NAc) shell. Although the effects of acetylcholine on the action potential properties of NAc medium spiny (MS) neurons have been reported, how intrinsic acetylcholine released from NAc cholinergic interneurons regulates the neural activity of MS neurons is still an open issue. To explore the cholinergic effects on the subthreshold responses and action potential properties of MS neurons in the NAc shell, we first tested the effects of carbachol, a non-selective cholinergic agonist, on MS neuronal activity. Then, we tested the effects of the activation of cholinergic interneurons on the electrophysiological properties of MS neurons via multiple whole-cell patch-clamp recordings. Bath application of carbachol induced resting membrane potential depolarization accompanied by an increase in the voltage response to negative current injection. These increases were blocked by the pre-application of pirenzepine, an M1 muscarinic receptor antagonist. In spite of the facilitative effect on voltage responses of negative current injection, carbachol diminished the characteristic slowly-depolarizing ramp potentials, which respond to positive current pulse injection. Thus, carbachol increased the rheobase and shifted the frequency-current curve toward the right. Repetitive spike firing of a cholinergic interneuron following positive current injection induced a similar increase in the rheobase, which delayed the action potential initiation in 38.9% MS neurons. In contrast to the bath application of carbachol, cholinergic interneuronal stimulation had little effect on the resting membrane potential in MS neurons. These results suggest that the acetylcholine released from a cholinergic interneuron is sufficient to suppress the repetitive spike firing of the adjacent MS neurons, although the depolarization of the resting membrane potential may require simultaneous activation of multiple cholinergic interneurons.