Selenoprotein dSelK in Drosophila elevates release of Ca2+ from endoplasmic reticulum by upregulating expression of inositol 1,4,5-tris-phosphate receptor

dSelK (G-rich), a homolog of human and mouse SelK, is one of three selenoproteins in Drosophila melanogaster. It is the only trans-membrane selenoprotein in D. melanogaster integrated into both the endoplasmic reticulum (ER) membrane and the Golgi apparatus. The gene expression profile of Drosophila Schneider 2 (S2) cells after the dsRNA interference (dsRNAi) targeting of dSelK was examined with the GeneChip Drosophila Genome 2.0 Array (Affymetrix), a high-density oligonucleotide microarray encompassing nearly the full Drosophila genome. The results showed that the transcriptional expression of eight genes whose proteins are located on (or related to) the ER or the Golgi apparatus was highly induced or repressed by the dsRNAi treatment. The mRNA levels of the inositol 1,4,5-tris-phosphate receptor (IP3 receptor), whose gene product is integrated into the ER membrane and regulates the release of Ca2+ from the ER to the cytosol, were significantly downregulated. In contrast, the expression of inositol 1,4,5-tris-phosphate kinase 1, which is a cytosolic protein with opposing functions to the IP3 receptor, was significantly upregulated. Quantitative real-time PCR verified these results. The concentration of intracellular free Ca2+ of the Drosophila S2 cells was significantly decreased after the knockdown of dSelK, whereas overexpression of dSelK significantly increased the intracellular free Ca2+ concentration. These results indicate that dSelK in D. melanogaster is involved in regulating the release of Ca2+ from the ER to the cytosol and may play important roles in the signal transduction pathways involving Ca2+ mobilization.

Surface and magnetic polaritons on two-dimensional nanoslab-aligned multilayer structure

The present study theoretically investigates the radiative properties of a two-dimensional (2-D) multilayer structure that has a dielectric spacer between a metallic substrate and square cross-sectional metallic gratings. Differently from the one-dimensional metallic strips coated on a dielectric spacer atop an opaque metallic film [Opt. Express 16, 11328 (2008)], the 2-D metallic gratings can support the localized surface plasmon in addition to the propagating surface plasmon along the metal-dielectric interface. Moreover, the presence of a dielectric spacer also allows the excitation of magnetic polaritons. Underlying mechanisms of the surface and magnetic polartions on the proposed structure are elucidated by employing the 2-D rigorous coupled-wave analysis. The results obtained in this study will advance our fundamental understanding of light-matter interaction at the nanometer scale and will facilitate the development of engineered nanostructures for real-world applications, such as thermophotovoltaic and photovoltaic devices.

Remifentanil alleviates transient cerebral ischemia-induced memory impairment through suppression of apoptotic neuronal cell death in gerbils

BACKGROUND

During neurosurgical procedures, patients are often exposed to hypoxic and ischemic brain damage. Cerebral ischemia leads to neuronal cell death and eventually causes neurological impairments. Remifentanil is a new ultra-short acting phenylpiperidine opioid analgesic. In this study, we evaluated remifentanil to determine if it exerts an anti-apoptotic effect in the hippocampal dentate gyrus following transient global ischemia in gerbils.

METHODS

Step-down avoidance task, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay, and immunohistochemical staining for caspase-3 were performed.

RESULTS

The numbers of TUNEL-positive cells and caspase-3-positive cells in the dentate gyrus were increased by ransient global ischemia. Latency in the step-down avoidance task was increased by transient global ischemia. Results revealed that apoptotic cell death in the dentate gyrus was increased significantly following transient global ischemia, resulting in memory impairment. However, treatment with remifentanil suppressed ischemia-induced apoptosis in the dentate gyrus, thereby alleviating the memory impairment that was induced by ischemic cerebral injury.

CONCLUSIONS

These results indicate that remifentanil may exert a neuroprotective effect on ischemic brain damage during surgery.

Design analysis of doped-silicon surface plasmon resonance immunosensors in mid-infrared range

This paper reports the design analysis of a microfabricatable mid-infrared (mid-IR) surface plasmon resonance (SPR) sensor platform. The proposed platform has periodic heavily doped profiles implanted into intrinsic silicon and a thin gold layer deposited on top, making a physically flat grating SPR coupler. A rigorous coupled-wave analysis was conducted to prove the design feasibility, characterize the sensor's performance, and determine geometric parameters of the heavily doped profiles. Finite element analysis (FEA) was also employed to compute the electromagnetic field distributions at the plasmon resonance. Obtained results reveal that the proposed structure can excite the SPR on the normal incidence of mid-IR light, resulting in a large probing depth that will facilitate the study of larger analytes. Furthermore, the whole structure can be microfabricated with well-established batch protocols, providing tunability in the SPR excitation wavelength for specific biosensing needs with a low manufacturing cost. When the SPR sensor is to be used in a Fourier-transform infrared (FTIR) spectroscopy platform, its detection sensitivity and limit of detection are estimated to be 3022 nm/RIU and ~70 pg/mm(2), respectively, at a sample layer thickness of 100 nm. The design analysis performed in the present study will allow the fabrication of a tunable, disposable mid-IR SPR sensor that combines advantages of conventional prism and metallic grating SPR sensors.

Development of postdural puncture headache following therapeutic acupuncture using a long acupuncture needle

Acupuncture appears to be a clinically effective treatment for acute and chronic pain. A considerable amount of research has been conducted to evaluate the role that acupuncture plays in pain suppression; however, few studies have been conducted to evaluate the side effects of the acupuncture procedure. This case report describes a suspected postdural puncture headache following acupuncture for lower back pain. Considering the high opening pressure, cerebrospinal fluid leakage, and the patient's history of acupuncture in the lower back area, our diagnosis was iatrogenic postdural puncture headache. Full relief of the headache was achieved after administration of an epidural blood patch.

Differences in the prevalence of colorectal polyps in patients undergoing endoscopic removal of gastric adenoma or early gastric cancer and in healthy individuals

BACKGROUND AND AIMS

We compared the prevalence of adenomatous and cancerous colon polyps in patients who underwent endoscopic removal of gastric neoplasms and in healthy controls.

MATERIALS AND METHODS

This retrospective study reviewed the medical records of 186 patients with gastric neoplasms and 186 healthy subjects from January 2002 to October 2008. The gastric neoplasm group was comprised of patients undergoing endoscopic removal of gastric adenomas or early gastric cancers and serial fiberoptic colonoscopy (FCS) for checkups. The control group was comprised of subjects undergoing fiberoptic esophagogastroduodenoscopy (FEGD) and FCS for general checkup and was matched for age and sex with the gastric neoplasm group. Advanced colonic neoplasm was defined by any of the following: (1) the presence of three or more polyps; (2) polyp size at least 1.0 cm; (3) high-grade dysplasia or adenocarcinoma confirmed by histopathologic examination.

RESULTS

Of the 372 persons, colorectal polyps were detected in 124 (33.3 %), advanced colonic neoplasms in 44 (11.8 %), and adenocarcinomas in 10 (2.7 %). The overall prevalence of adenomatous or cancerous polyps ("all polyps") and the prevalence of advanced colonic neoplasms were significantly higher in the gastric neoplasm group than in the control group (all polyps: 40.9 % in the gastric neoplasm group vs. 25.8 % in the control group, P = 0.002; advanced colonic neoplasms: 15.6 % vs. 8.1 %, P = 0.025). The risk factors for all polyps were age, male sex, diabetes mellitus, and being assigned to the gastric neoplasm group, and those for advanced colonic neoplasms were age and being assigned to the gastric neoplasm group. Confining the analysis to the gastric neoplasm group, the risk factors for all polyps were identical with those for the total group; however, those for advanced colonic neoplasm were different (age vs. diabetes and hypertriglyceridemia).

CONCLUSION

Endoscopists should consider performing routine FCS in patients undergoing endoscopic removal of gastric neoplasms.

Pseudomeningocele after lumbar discectomy treated with fibrin glue and epidural blood patch: A case report

Pseudomeningocele is rare complication after lumbar discectomy. Most pseudomeningoceles are asymptomatic, but sometimes can cause headaches, infection, back pain, and radicular pain. Treatment modalities include conservative management, epidural blood patch, lumbar subarachnoid drainage, and surgery. We report a successful treatment of pseudomeningocele with epidural blood and fibrin glue patch, which did not treated with conservative management and epidural blood patch alone.

Devastation of bone tissue in the appendicular skeleton parallels the progression of neuromuscular disease

A mouse model of spinal muscular atrophy with respiratory distress (SMARD1) was used to study the consequences of neuromuscular degenerative disease on bone quantity and morphology. Histomorphometry and micro-computed tomography were used to assess the cortical and cancellous bone in the tibia, femur and humerus of adult neuromuscular degeneration (nmd) mice (up to 21w) and age-matched wild-type controls (WT). At 21w, the average lengths of the humerus, tibia and femur were 15%, 10%, and 10% shorter in the nmd mice, respectively. The midshaft of the humerus, tibia and femur of nmd mice had 41%, 47% and 34% less cortical bone than the WT. In the humeral, tibial, and femoral metaphyses of the nmd mice, there was 50%, 78%, and 85% less trabecular bone volume, and 58%, 92%, and 94% less trabecular connectivity than the WT. NMD cortical bone had less than half of the 42% active surface measured in the WT, yet the mineral apposition rate of those surfaces were similar between strains (nmd: 1.80 microm x day(-1); WT: 2.05 microm x day(-1)). Osteoclast number and activity levels did not differ across strains. These data emphasize that neuromuscular degeneration as a result of immunoglobulin S-mu binding protein-2 (Ighmbp2) mutation will compromise several critical parameters of bone quantity and architecture, the most severe occurring in the trabecular compartment.

Visible and near-infrared radiative properties of vertically aligned multi-walled carbon nanotubes

This work investigates the reflection and scattering from vertically aligned carbon nanotubes, fabricated on silicon substrate using thermally enhanced chemical vapor deposition with both tip-growth and base-growth mechanisms. The directional-hemispherical reflectance in the visible and near-infrared wavelengths was measured with an integrating sphere. The polarization-dependent bidirectional reflectance distribution function was characterized with a laser scatterometer at the wavelength of 635 nm. The effective medium theory was used to elucidate the mechanism of high absorptance (greater than 0.97 in the spectral region from 400 to 1800 nm) of the multi-walled carbon nanotube samples. It is observed that scattering by impurities on the top of the nanotubes, by the nanotube tips, and by defects and misalignment can significantly increase the reflectance and introduce retroreflection. This study may facilitate application of carbon nanotubes in pyroelectric detectors as well as thermophotovoltaic emitters and absorbers.

Light scattering of semitransparent sintered polytetrafluoroethylene films

Polytetrafluoroethylene (PTFE) is a strongly scattering material and has been regarded to have optical properties similar to biological tissues. In the present study, the bidirectional reflectance distribution function (BRDF) and the bidirectional transmittance distribution function (BTDF) of several PTFE films, with thicknesses from 0.11 to 10 mm, are measured using a laser scatterometer at the wavelength of 635 nm. The directional-hemispherical reflectance (R) and transmittance (T) were obtained by integrating BRDF and BTDF for normal incidence. Comparison of the ratio of the measured R and T with that calculated from the adding-doubling method allows the determination of the reduced scattering coefficient. Furthermore, the effect of surface scattering is investigated by measuring the polarization-dependent BRDF and BTDF at oblique incidence. By analyzing the measurement uncertainty of BTDF in the near-normal observation angles at normal incidence, the present authors found that the scattering coefficient of PTFE should exceed 1200 cm(-1), which is much greater than that of biological tissues. On the other hand, the absorption coefficient of PTFE must be less than 0.01 cm(-1), much smaller than that of biological tissues, a necessary condition to achieve R > or =0.98 with a 10-mm-thick slab.

Coherent thermal emission by excitation of magnetic polaritons between periodic strips and a metallic film

The present paper theoretically demonstrates coherent thermal emission in the infrared region by exciting magnetic polaritons between metallic gratings and an opaque metallic film, separated by a dielectric spacer. The coupling of the metallic strips and the film induces a magnetic response that is characterized by a negative permeability and positive permittivity. On the other hand, the metallic film intrinsically exhibits a negative permittivity and positive permeability in the near infrared. This artificial structure is equivalent to a pair of single-negative materials. By exciting surface magnetic polaritons, large emissivity peaks can be achieved at the resonance frequencies and are almost independent of the emission angle. The resonance frequency of the magnetic response can be predicted by an analogy to an inductor and capacitor circuit. The proposed structure can be easily constructed using micro/nanofabrication.

Hyperthermal neutral beam sources for material processing

Hyperthermal neutral beams have a great potential for material processes, especially for etching and thin film deposition for semiconductor and display fabrication as well as deposition for various thin film applications. Plasma-induced damage during plasma etching is a serious problem for manufacturing deep submicron semiconductor devices and is expected to be a problem for future nanoscale devices. Thermal and plasma-induced damage is also problematic for thin film depositions such as transparent conductive oxide films on organic light emitting diodes or flexible displays due to high temperature processes in plasma environments. These problems can be overcome by damage-free and low-temperature processes with hyperthermal neutral beams. We will present the status of the hyperthermal neutral beam development and the applications, especially, in semiconductor and display fabrication and introduce potential applications of thin film growing for optoelectronic devices such as light emitting diodes.

Surface waves between metallic films and truncated photonic crystals observed with reflectance spectroscopy

We have analyzed and demonstrated surface-wave excitations, by propagating waves in air, at the interface between a truncated photonic crystal (PC) and a silver film in the near-infrared. The truncated PC was fabricated with several unit cells of alternating SiO(2) and Si(3)N(4) layers. The dispersion relation of surface waves was calculated using the supercell method. A Fourier-transform infrared spectrometer measured the spectral reflectance of the fabricated sample at different incidence angles. An angle-resolved laser scatterometer measured the reflectance as a function of the incidence angle at the wavelength of 891 nm. The agreement between the resonance conditions obtained from experiments and the calculated dispersion relation manifests that surface waves at the PC-Ag interface may be utilized to build coherent thermal-emission sources.