Dynamical visualization of anisotropic electromagnetic re-emissions from a single metal micro-helix at THz frequencies.

The capability for actual measurements-not just simulations-of the dynamical behavior of THz electromagnetic waves, including interactions with prevalent 3D objects, has become increasingly important not only for developments of various THz devices, but also for reliable evaluation of electromagnetic compatibility. We have obtained real-time visualizations of the spatial evolution of THz electromagnetic waves interacting with a single metal micro-helix. After the micro-helix is stimulated by a broadband pico-second pulse of THz electromagnetic waves, two types of anisotropic re-emissions can occur following overall inductive current oscillations in the micro-helix. They propagate in orthogonally crossed directions with different THz frequency spectra. This unique radiative feature can be very useful for the development of a smart antenna with broadband multiplexing/demultiplexing ability and directional adaptivity. In this way, we have demonstrated that our advanced measurement techniques can lead to the development of novel functional THz devices.

Transfer of orbital angular momentum of light to plasmonic excitations in metamaterials.

The emergence of the vortex beam with orbital angular momentum (OAM) has provided intriguing possibilities to induce optical transitions beyond the framework of the electric dipole interaction. The uniqueness stems from the OAM transfer from light to material, as demonstrated in electronic transitions in atomic systems. In this study, we report on the OAM transfer to electrons in solid-state systems, which has been elusive to date. Using metamaterials (periodically textured metallic disks), we show that multipolar modes of the surface electromagnetic excitations (so-called spoof localized surface plasmons) are selectively induced by the terahertz vortex beam. Our results reveal selection rules governed by the conservation of the total angular momentum, which is confirmed by numerical simulations. The efficient transfer of light's OAM to elementary excitations in solid-state systems at room temperature opens up new possibilities of OAM manipulation.

Expression pattern of Galectin 4 in rat placentation.

Galectin 4 (Gal4) is abundantly expressed in the epithelium of the gastrointestinal tract, and functional analysis has concentrated on its roles associated with polarized membrane trafficking. This study aimed to investigate the expression of Gal4 in placentation. The expression level of Gal4 was revealed to be lower in differentiated Rcho-1 cells (a model system of rat trophoblast differentiation) than in proliferative cells. In the rat placenta, immunohistochemical analysis showed that Gal4 is preferentially located in the maternal-fetal junctional zone. These results suggest that down-regulation of Gal4 may be involved in the promotion of trophoblast cell differentiation.

Involvement of retinoic acid-inducible gene-I in inflammation of rheumatoid fibroblast-like synoviocytes.

Interferon (IFN)-gamma is a major cytokine that regulates T helper 1-type immune reactions and serves as an important mediator in the pathogenesis of autoimmune diseases. Retinoic acid-inducible gene-I (RIG-I) is an IFN-gamma-inducible gene and known to be involved in the inflammatory and immune reactions. In the present study, we found high levels of RIG-I expression in synovial tissues of rheumatoid arthritis (RA), while the expression in osteoarthritis tissues was low. Treatment of cultured fibroblast-like synoviocytes with IFN-gamma markedly induced the expression of RIG-I. Knockdown of RIG-I in fibroblast-like synoviocytes, with specific siRNA, resulted in the inhibition of the IFN-gamma-induced expression of chemokine (C-X-C motif) ligand 10 (CXCL10)/IFN-gamma-inducible protein-10 (IP-10), a chemokine with chemotactic activity towards T cells. These findings suggest that RIG-I may play an important role in the pathogenesis of synovial inflammation in RA, at least in part, by regulating the IFN-gamma-induced expression of CXCL10/IP-10.

The relationship between persistent secretion of RANTES and residual infiltration of eosinophils and memory T lymphocytes after Helicobacter pylori eradication.

Helicobacter pylori (HP)-infected gastric mucosa displays a conspicuous infiltration of mononuclear cells as well as neutrophils. RANTES is a potent chemoattractant peptide for memory T lymphocytes and eosinophils. RANTES protein concentration and the numbers of RANTES-, CD45RO-, and major basic protein (MBP)-positive cells were therefore evaluated in the gastric mucosa from 51 patients with HP-positive chronic gastritis before and after HP eradication and from 22 HP-negative healthy volunteers. RANTES protein concentration was significantly elevated in HP-positive cases and remained high after HP eradication. The numbers of RANTES-, CD45RO-, and MBP-positive cells were significantly increased in HP-positive cases and were well correlated with RANTES protein levels. All tended to decrease after HP eradication, but did not reach the level of HP-negative cases, even at 24 months after HP eradication. It was concluded that persistent expression and secretion of RANTES were closely related to residual infiltration of memory T lymphocytes and eosinophils, for a prolonged period after HP eradication. This seems to be an important mechanism of prolonged gastric mucosal immune response against HP infection, even after HP eradication, and of persistent mucosal damage and atrophy.

[Changes in the fractal component of spectral analysis of heart rate variability and systolic blood pressure variability during the head-up tilt test].

Blood pressure and heart rate change are related to the level of physical activity, and are correlated with each other. Heart rate and blood pressure signals were investigated by coarse graining spectral analysis and changes in the harmonic and non-harmonic (fractal) power were examined during the head-up tilt test. Fourteen healthy subjects, 9 men and 5 women (mean age 30.4 +/- 1.0 years) completed the test protocol of 15 min supine rest followed by the head-up tilt (80 degrees) test. Heart rate was measured continuously with standard bipolar leads and electrocardiography. A finger cuff was placed on the left index finger for beat-by-beat recording of systolic blood pressure based on the continuous noninvasive method, and the impulse train was stored on a personal computer for spectral analysis. The harmonic component, the integrated powers in the low-frequency and high-frequency regions, and the fractal component were then calculated. The fractal component was plotted on a log power versus log frequency plane with spectral index beta estimated as the slope of the linear regression of this 1/f beta plot. RR-interval was significantly shorter during the head-up tilt position than in the supine rest position with a marked reduction in the high-frequency power. The ratio of fractal component for total power was increased and the slope beta of the 1/f beta relationship was significantly greater in the head-up tilt (1.61 +/- 0.05) than in the supine rest (0.92 +/- 0.07) position. Systolic blood pressure showed a significant increase during head-up tilt, and marked increases in high-frequency power and fractal power. However, both the ratio of fractal component for total power and the slope beta remained unchanged. Further studies are needed to clarify whether the slope beta is essentially stable or variable in some conditions.

[The expression of chemokines and the dynamics of inflammatory cell infiltration before and after H. pylori eradication].

We attempted to evaluate the relationship between the expression of IL-8 and RANTES and the dynamics of their target cells in human gastric mucosa of H. pylori associated gastritis, including their changes after H. pylori eradication. We performed the measurement of the mucosal level of IL-8 and RANTES protein by ELISA and immunohistochemistry. The neutrophil infiltration into the gastric mucosa was identified by the histological examination based on the Updated Sydney system and the measurement of MPO activity. The memory T lymphocyte and eosinophil were indicated by immunohistochemistry of CD45RO that is one of surface markers indicating memory T lymphocytes and MBP that is contained in the granules of eosinophils. H. pylori positive gastric mucosa demonstrated a remarkable increase in neutrophils. CD45RO positive cells and eosinophils, compared to H. pylori negative gastric mucosa. Gastric mucosal level of IL-8 and RANTES protein and MPO activity was significantly higher in H. pylori positive cases than that in H. pylori negative controls after H. pylori eradication, both of the level of IL-8 protein and MPO activity reduced at the same levels as negative controls. However, RANTES expression, CD45RO positive T lymphocytes and eosinophils remained in H. pylori eradicated gastric mucosa at the significantly high level, compared with H. pylori negative cases. Therefore, it seems possible that IL-8 might enhance the inflammation by facilitating the neutrophil infiltration into H. pylori infected gastric mucosa and that RANTES might play an important role in the specific immune response against H. pylori and the maintenance of the immune memory after H. pylori eradication.

Immunohistochemical studies on EGF family growth factors in normal and ulcerated human gastric mucosa.

Expression of members of the epidermal growth factor family, including epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha), amphiregulin (AR), and Cripto, as well as their putative receptor, epidermal growth factor receptor (EGFR), was studied immunohistochemically in human gastric mucosa to evaluate their possible roles in cell proliferation of normal and regenerative gastric mucosa. We also examined the correlation betwen cell proliferation and EGFR by double immunohistochemical staining for proliferating cell nuclear antigen (PCNA) and EGFR. In normal gastric mucosa, TGF-alpha, Cripto, and AR immunoreactivities were observed in the surface epithelial and parietal cells of gastric fundic glands, respectively. EGF immunoreactivity was not observed in any of normal mucosa examined. EGFR immunoreactivity was detected on foveolar cells in proliferative zones and in parietal cells. Double immunostaining revealed that EGFR immunoreactivity was distributed much more widely than PCNA immunoreactivity. PCNA positive epithelial cells adjacent to gastric ulcer margin expressed relatively intense EGFR but did not express any of the growth factors examined. On the other hand, relatively intense immunoreactivity of both TGF-alpha and Cripto was detected in PCNA-negative regenerative epithelium located distant from gastric ulcer margin. Relative immunoreactivity of AR in regenerative gastric epithelium associated with ulcer was not different from that in normal gastric mucosa. TGF-alpha, AR, and Cripto are considered to play important roles in normal gastric mucosal proliferation, and TGF-alpha and Cripto may be involved in ulcer healing, possibly via a paracrine mechanism.

[Methodological study of 13C-urea breath test for detection of Helicobacter pylori infection].

In this study, we investigate simple breath test for detection of Helicobacter pylori (HP) infection using 13C-urea. Thirty-nine patients (30 were HP positive, 9 were HP negative) were given three different doses (50, 100 and 150 mg) of 13C-urea at fasting, and keep sitting after mouth washing with water. Breath samples were taken before and 10, 20, 30, 45, and 60 minutes after urea administration. More than 100mg of 13C-urea was necessary for correct diagnosis of HP infection, because 2 HP positive cases were not detected by 50mg 13C-urea administration. In cases with patchy distribution of HP in the stomach, it may be necessary to change the posture to distribute urea within the whole stomach. In most of HP positive cases, peak delta 13CO2 were obtained within 30 minutes, but one HP negative case showed high delta 13CO2 at 10 minutes, which was probably caused by urease activity in the mouth. So it is appropriate to take breath sample at 20 minutes after urea administration. In this study, cut-off value for a positive test can be setted between 4 to 7 delta/1000, it is necessary to investigate much more cases to set exact cut-off value.

[Left ventricular failure following valve replacement surgery in patients with mitral stenosis--its genesis, prognosis, and the method for the preoperative prediction].

To detect the genesis and the prognosis of left ventricular failure (LVF) following the valve replacement surgery to mitral stenosis (MS), preoperative values and postoperative courses were assessed in 90 patients with MS. The criteria for LVF were as follows: postoperative severe left ventricular (LV) dysfunction which required intra-aortic balloon pumping (IABP) support with large doses of catecholamine. Among these 90 patients, LVF had occurred in 13 patients, of which 6 had a definite cause of LVF (group A), but the other 7 patients failed to LVF despite uneventful operation (group B). Comparing the pre- and postoperative values in these two groups, the duration of IABP support was much longer in group A, and the weaning rate from IABP was also poor in this group. Long-term survival was achieved only by one patient in group A, whereas 5 out of 6 patients of group B survived long-term postoperatively. Evaluating the preoperative LV function in group B patients, depressed LV function [%fractional shortening (%FS) less than or equal to 27%] was observed in 5 patients. Among these 5 patients, three had low cardiac output; in other two, preoperative %FS was severely depressed. In such patients, the responses to preoperative dobutamine administration tests were poor, and the values of %fibrosis of the LV myocardium, which was demonstrated by intraoperative biopsy, was greater in them. In conclusion, the causes of postoperative LVF following the mitral valve replacement to MS was divided into two categories: one due to perioperative complication and another due to preoperatively impaired LV function.(ABSTRACT TRUNCATED AT 250 WORDS)

[The influence of left ventricular function on surgical risk in mitral stenosis].

The influence of left ventricular (LV) function on surgical risk was assessed in 98 patients with mitral stenosis (MS) using echocardiographic studies including a dobutamine test in 42 cases. Intraoperative LV myocardial biopsy was also performed in 24 cases. Preoperatively, depressed LV function [% fractional shortening (%FS) less than or equal to 27%] was observed in 21 patients (21%). Seven patients had postoperative LV failure, five of whom had preoperative depression of LV function. Among these five patients, three had low cardiac output; and in the other two preoperative %FS was severely depressed. In cases of poor responses to preoperative dobutamine, postoperative improvement in %FS and the cardiac index were not as marked in the good-response group, and some of these patients had LV failure postoperatively. Percent fibrosis of the LV myocardium, which was demonstrated by intraoperative biopsy, correlated negatively with preoperative %FS, and %fibrosis was greater in the group responding poorly to dobutamine administration, especially in patients with postoperative LV failure. These results suggest that some patients with MS were developing LV failure postoperatively due to impaired myocardium. Myocardial fibrosis seemed to be an important causative factor in these patients. Preoperative evaluation utilizing dobutamine administration is useful in screening for high-risk patients.

Cadmium-induced proximal tubular dysfunction in a cadmium-polluted area.

Health examinations were performed in 147 people living in a cadmium-polluted area, Kosaka Town, Japan. 33 of 147 residents had some indications of proximal tubular dysfunction, such as renal glucosuria, tubular proteinuria, and aminoaciduria, and 10 of them were diagnosed as having multiple proximal tubular dysfunctions. Detailed examinations revealed that none of the cases had any causal diseases other than chronic cadmium poisoning. Residents' mean cadmium intake and mean urinary cadmium concentration were over 3 times as high as those in control areas. From these findings, renal lesions identified in these residents were concluded as chronic cadmium poisoning induced by environmental cadmium pollution.