In-situ observation of atomic processes in Xe nanocrystals embedded in al

Self-organization processes in Xe nanocrystals embedded in Al are observed with in-situ high-resolution electron microscopy. Under electron irradiation, stacking fault type defects are produced in Xe nanocrystals. The defects recover in a layer by layer manner. Detailed analysis of the video reveals that the displacement of Xe atoms in the stacking fault was rather small for the Xe atoms at boundary between Xe and Al, suggesting the possibility of the stacking fault in Xe precipitate originating inside of precipitate, not at the Al/Xe interface.

Sub-10 nm crystalline silicon nanostructures by electron beam induced deposition lithography

A novel top-down approach for the controllable fabrication of semiconductor nanostructures exhibiting quantum effects is described. By decomposing metal-rich precursor gas molecules with an electron beam, a sub-10 nm metal pattern can be formed and subsequently transferred to a semiconductor substrate. In such a way monocrystalline silicon nanodots and nanowires are produced as revealed by transmission electron microscopy. It is also shown how through controlled thermal or chemical oxidation the nanostructure surface can be passivated. By providing direct access to the sub-10 nm size range this method possesses promising potential for application in the quantum dot and nanoelectronics fields.

A nanosized photodetector fabricated by electron-beam-induced deposition

A sensitive nanosized molybdenum oxide (MoO(x)) photodetector is manufactured at a desired position by electron-beam-induced deposition (EBID). As-deposited MoO(x) had a conductivity approximately 300 S cm(-1). After 2 h annealing at 573 K, the conductivity of nanowires decreased 10 times to approximately 30 S cm(-1) and MoO(x) had photoconductivity. Nanosized MoO(x) wires enhanced the sensitivity of optical devices due to an increased surface area to volume ratio.

Thickness measurements with electron energy loss spectroscopy

Measurements of thickness using electron energy loss spectroscopy (EELS) are revised. Absolute thickness values can be quickly and accurately determined with the Kramers-Kronig sum method. The EELS data analysis is even much easier with the log-ratio method, however, absolute calibration of this method requires knowledge of the mean free path of inelastic electron scattering lambda. The latter has been measured here in a wide range of solids and a scaling law lambda approximately rho(-0.3) versus mass density rho has been revealed. EELS measurements critically depend on the excitation and collection angles. This dependence has been studied experimentally and theoretically and an efficient model has been formulated.

High-resolution electron microscopy of detonation nanodiamond

The structure of individual nanodiamond grains produced by the detonation of carbon-based explosives has been studied with a high-vacuum aberration-corrected electron microscope. Many grains show a well-resolved cubic diamond lattice with negligible contamination, thereby demonstrating that the non-diamond shell, universally observed on nanodiamond particles, could be intrinsic to the preparation process rather than to the nanosized diamond itself. The strength of the adhesion between the nanodiamond grains, and the possibility of their patterning with sub-nanometer precision, are also demonstrated.

The squamous cell carcinoma antigens as relevant biomarkers of atopic dermatitis

BACKGROUND

Although it is thought that both Th1- and Th2-type inflammations are involved in the pathogenesis of atopic dermatitis (AD), it is controversial which immune response is more involved in regulating the clinical severity of AD. We recently found that the squamous cell carcinoma antigens 1 (SCCA1) and SCCA2 are novel biomarkers of bronchial asthma, downstream of IL-4 and IL-13.

OBJECTIVE

We examined whether SCCA1 and SCCA2 could also serve as biomarkers of AD, reflecting its Th2-type immune responses, and whether the expression level of SCCA was correlated with clinical severity of AD.

METHOD

We compared the expression of SCCA1 and SCCA2 at the mRNA and protein levels in both involved and uninvolved skin of AD patients and in normal control skin. We next analysed induction of SCCA by IL-4 or IL-13 in keratinocytes. Finally, we compared the serum level of SCCA with laboratory parameters reflecting Th2-type inflammation and clinical severity in AD patients.

RESULTS

SCCA1 and SCCA2 were highly expressed in involved skin of AD patients, compared with their uninvolved skin, at both mRNA and protein levels. SCCA protein was dominantly expressed in suprabasal keratinocytes in the epidermis of AD patients. Either IL-4 or IL-13, but not IFN-gamma or TNF, induced production of SCCA in keratinocytes. These result suggest that SCCA is induced in AD skin, probably due to direct actions of IL-4 and/or IL-13 on keratinocytes. Serum levels of SCCA were well correlated with eosinophil numbers and serum lactate dehydrogenase levels, and weakly with serum IgE levels, in AD patients. Furthermore, serum levels of SCCA were strongly correlated with clinical severity.

CONCLUSIONS

Th2-type inflammation dominantly regulates the clinical severity of AD, and SCCA is a relevant biomarker of AD, reflecting both Th2-type inflammation and clinical severity.

Dynamic profile calculation of deposition resolution by high-energy electrons in electron-beam-induced deposition

The effect of the accelerating voltage of incident electrons on the resolution of electron-beam-induced deposition was investigated by a dynamic Monte Carlo profile simulator which includes the electron scattering in the already grown deposit structure. By simulating the deposition at two different accelerating voltages of 20 and 200 kV with an idealistic zero-diameter incident probe on a bulk substrate, it was revealed that the smaller size structures were attainable by 200 keV than by 20 keV. The effect of the substrate was also argued by comparing the above results with the simulation results obtained for a point-like starting substrate. Surprisingly, the shapes of the deposits grown on bulk substrates were reproduced well by the simulations starting from point-like substrates indicating the small effect of the substrate on the shape of deposits.

Structure of nanometre-sized Xe particles embedded in Al crystals

The structure and lattice parameters of Xe particles about 1 nm to about 6 nm in size embedded in Al were investigated with off-Bragg condition high-resolution transmission electron microscopy. An Xe particle about 1 nm in size had different structural properties from those 2-6 nm in sizes. Some 1-nm Xe particles had an face-centred cubic (f.c.c.) structure with the same orientation as the Al matrix, whereas others of the same size had a non-f.c.c. structure. The lattice parameters of a 1-nm f.c.c. Xe particle were about 20% smaller than the average value obtained from electron diffraction, i.e. the particle was compressed by about 80%. The lattice parameters of Xe crystals about 2 nm to about 6 nm in size were almost the same as those obtained from diffraction results. One of the reasons for the extra compression seen with a 1-nm Xe particle is the increase in pressure inside an Xe particle with decreasing particle size.

Possible mechanisms of gender bias in SLE: a new hypothesis involving a comparison of SLE with atopy

The prevalence of systemic lupus erythematosus (SLE) is far higher in females than in males, and numerous investigations of this gender bias have been performed from several perspectives. Sex hormones, particularly estrogens, may be significant in causing the gender discrepancy. This article discusses the possible importance of estrogens in regulating the expression of and responsivity to autoantigens in SLE and in atopic disorders, which are associated with hyperreactivity to exogenous antigens. Estrogens seem to play an important role in the overexpression of endogenous autoantigens, such as human endogenous retroviruses (HERV), and this may be related to the existence of a gender bias in the incidence of SLE but not atopy.

Application of transmission electron microscopes to nanometre-sized fabrication by means of electron beam-induced deposition

Electron beam-induced deposition was carried out using a scanning transmission electron microscope with a field emission gun to fabricate nanometre-sized structures. A small amount of a metal-organic gas was introduced near the substrate in the microscope chamber, and focused electron beams were irradiated. Two- and three-dimensional structures were fabricated by scanning the beam position. The minimum line width of the freestanding structures was 8 nm at a constant gas flux used. This line width of 8 nm is considered to be achieved by employing a high accelerating voltage, which leads to a small probe size, and the optimum scanning speed.

Observation of nanometer-Xe clusters embedded in Al crystals

The structure of Xe precipitates with sizes in several nanometers embedded in Al is known to be stable and its structure is well confirmed. But knowledge about the structure of Xe precipitates with nanometer sizes is very limited. There are difficulties in observing such small structures embedded in a crystalline matrix. An off-Bragg condition is used to observe diffraction patterns, dark-field, and high-resolution transmission electron microscopy images. The structure of Xe precipitates with sizes of about 2 nm and smaller is observed and confirmed. They are in an fcc structure and their orientation relationship with the Al matrix is similar to that of larger crystalline Xe precipitates or in an undefined structure. The lattice spacing or atomic distance in such nanometer-sized Xe precipitates is smaller than those of larger Xe precipitates embedded in Al matrix. There is a trend that as the size becomes smaller, the precipitates are more likely to have an undefined structure.

Layer-doubling method in ADF-STEM image simulation

A layer-doubling method developed in LEED calculation is applied to the ADF-STEM image simulation. This approach makes it possible to simulate image intensities of systems having a repeated slab structure, such as embedded precipitates or defects, with a much higher efficiency because it does not require the diagonalization of repeated slabs. As a simple example of this method, channeling effects are calculated for a system with embedded crystalline displaced slabs for various different slab thicknesses.

In situ observation of the formation of Fe3O4 in Fe4N (001) due to electron irradiation

gamma(')-Fe4N was subjected to electron irradiation with the dose rate of 6.8 x 10(23)e m(-2) s(-1) in a 400 kV transmission electron microscope. The first in situ observation of the formation of Fe3O4 (O) on Fe4N (gamma(')) with the orientation relationship of [100](O) parallel [100](gamma(')) and <001>(O) parallel <001>(gamma(')) has been made inside the microscope with the basic column vacuum of (5-6) x 10(-5) Pa. A mechanism is proposed involving the electron-stimulated dissociation of Fe-N chemical bonds, desorption of nitrogen from the surface, adsorption of oxygen to the surface, and the oxidization of excessive metallic iron on the surface.

Primary cutaneous nocardiosis with multiple, subcutaneous abscesses in a patient with sarcoidosis

A case of multiple subcutaneous nocardial abscesses is reported in a patient who received systemic corticosteroids over a period of about 4 years for the treatment of visceral sarcoidosis. The diagnosis of subcutaneous abscess caused by Nocardia asteroides was made based on bacteriological examination. It could not be determined before treatment whether the abscesses represented primary or secondary nocardiosis. Surgical drainage and systemic administration of minocycline hydrochloride dramatically resolved the cutaneous lesions. To the authors' knowledge, this is the first reported case in Japan of primary cutaneous nocardiosis in a patient with sarcoidosis.

Transforming growth factor-beta1 suppresses atopic dermatitis-like skin lesions in NC/Nga mice

BACKGROUND

Atopic dermatitis is a chronic, relapsing inflammatory disorder characterized by pruritic and eczematous skin lesions. Transforming growth factor (TGF)-beta1 has been implicated in the suppression of inflammatory responses.

OBJECTIVE

The purpose of this study is to determine whether TGF-beta1 suppresses skin lesions in a mouse model of atopic dermatitis.

METHODS

We used the NC/Nga strain of mice as an in vivo model of atopic dermatitis. The effects of exogenous TGF-beta1 on atopic dermatitis-like skin lesions in NC/Nga mice were evaluated clinically, histologically and immunologically.

RESULTS

Subcutaneous injection of recombinant TGF-beta1 macroscopically suppressed eczematous skin lesions in NC/Nga mice associated with reduced serum immunoglobulin E (IgE) levels. Histological analysis showed that TGF-beta1 significantly inhibited the infiltration of inflammatory cells such as mast cells and eosinophils into the skin of NC/Nga mice. Spontaneous interferon (IFN)-gamma production from splenocytes of NC/Nga mice was down-regulated by the treatment with TGF-beta1 and neutralizing antibody against IFN-gamma inhibited skin lesions in NC/Nga mice. The inhibitory effect of TGF-beta1 on the skin lesions lasted at least 1 week after cessation of the treatment.

CONCLUSION

These findings indicate that TGF-beta1 suppressed atopic dermatitis-like skin lesions in NC/Nga mice at least in part through down-regulation of IFN-gamma. These results suggest that TGF-beta1 may have a therapeutic potential for atopic dermatitis.

Establishment and characterization of a murine mast cell line derived from NC/Nga mice

A cell line, termed NCJ, was established from the bone marrow-derived mast cells (BMMCs) of NC/Nga mice that are mouse models for atopic dermatitis. NCJ cells expressed FcepsilonRI and c-kit and showed a metachromasia of the granules with a toluidine blue-positive and safranin-negative staining pattern that is characteristic for immature-type mast cells. Interestingly, NCJ cells showed proliferation independent of IL-3, which was associated with constitutive phosphorylation of Raf-1 and Erk kinases. Although NCJ cells had several characteristics of mast cells, we failed to detect FcepsilonRI-mediated beta-hexosaminidase release and its histamine content. These findings indicated that NCJ cells represented a mast cell line with an immature phenotype and the ability to proliferate in the absence of mast cell growth factors. NCJ cells might thus be useful to study the molecular basis of mast cell proliferation.

New scheme for calculation of annular dark-field STEM image including both elastically diffracted and TDS waves

A new scheme of calculation of high-angle annular dark-field STEM image, capable of including both elastically diffracted and thermal diffuse scattering waves, has been presented by a combination of Pennycook's and Nakamura's methods. The new scheme has been demonstrated for image simulations of Si(011) as functions of thickness, defocus values and detector angles. In the present method, the TDS electron intensities are treated in the same way as in Pennycook's method, having a clear physical picture of its origin and reflecting the atom configuration in the systems. For the case of Si(011), it has been confirmed that at the detector angle of 60 to 160 mrad, which is usually applied, the image becomes highly incoherent, and even the image formed only from SOLZ beams becomes incoherent at the detector angle. At a low detector angle, however, the image has coherent features indicating the necessity of a simulation for individual systems.

High-angle annular dark-field STEM observation of Xe nanocrystals embedded in Al

High-angle annular dark-field scanning transmission electron microscope (HAADF-STEM) observation of Xe precipitates embedded in crystalline membranes has been made using electron probes of atomic dimensions and HAADF-STEM images of Xe precipitates qualitatively different from conventional TEM observation results have been obtained. Multislice-based HAADF-STEM simulation has been made and it has been revealed that the intensity of images of Xe atoms at positions displaced from Al matrix columns decreases rapidly as the thickness increases. Even in a thin specimen, the off-site Xe atoms of the precipitate at deep locations, were not observable. Therefore, different images are expected for specimens of different thicknesses or depths of these precipitates. These results indicate that the observation of precipitates in crystalline membranes requires some care.

[The effect of suplatast tosilate on immunological parameters for the patients with atopic dermatitis]

A dose of 300 mg/day of suplatast tosilate was administered to one hundred one cases of atopic dermatitis for eight weeks, and the severity scores, peripheral blood eosinophil count, total serum IgE levels, plasma eosinophil cationic protein (ECP) levels, and other immunological parameters before and after the trial were observed and comparatively examined. The results are as follows: 1) Temporary improvements were found in the scores of severity and itchiness on all evaluated skin regions (face, limbs, and trunk). These scores decreased significantly for all observation periods at two, four, six and eight weeks after administration of suplatast tosilate compared with those before the administration (p < 0.01). 2) There was no sign of adverse effects on the drug. In the blood tests, one patient displayed elevated levels of GPT and another showed elevated total bilirubin. In the urine test (qualitative test), one case with positive urinary protein was observed. 3) Clinical examinations including assessment of the immunologic parameters were conducted at an average of 8.68 +/- 0.36th week. The peripheral blood eosinophil count, the percentage of eosinophil, and plasma ECP levels significantly diminished compared with those before administration, but no significant difference was found in total serum IgE levels and LDH levels. 4) The subjects were divided into two groups, one in which the clinical scores were improved by more than five and another with scores of less than five (including worsening), and the fluctuation of the immunological parameters (values before and after administration of the drug) of the two groups were compared. As a result, a significant difference was observed in the plasma ECP levels (p = 0.02) and peripheral blood eosinophil count (p = 0.091), but no difference was observed in total serum IgE levels and LDH levels. From the above mentioned results, the high efficacy and safety of suplatast tosilate in the treatment of severe atopic dermatitis were confirmed. At the same time, a decrease in the peripheral blood eosinophil count and the serum ECP levels were observed, suggesting the possibility that these values could be used as indices of the severity of atopic dermatitis.

NC/Nga mice: a mouse model for atopic dermatitis

Atopic dermatitis (AD) is a common pruritic disease that occurs primarily in infancy and childhood. AD is characterized by itching and the patient having an individual or family history of atopic diseases. Although AD is also frequently associated with elevated serum IgE levels and with common environmental factors contributing to its pathogenesis, the etiology of AD is still unknown. We examined NC/Nga mice (NC mice) that showed AD-like skin lesions with aging as a possible mouse model for AD. NC mice were maintained under conventional (Conv) or specific pathogen-free (SPF) conditions. Clinical symptoms, serum IgE levels and histopathology of the skin were compared between these 2 groups, and we explored their application as a model of human AD. It was found that the skin lesions of inbred NC mice were clinically and histologically very similar to human AD when the mice were raised under Conv conditions, but not under SPF conditions, and we assumed that some kinds of environmental factors might trigger AD-like signs and symptoms in NC mice. To further investigate the pathophysiology and treatment of AD, a suitable animal model is absolutely required, and NC mice are very useful for this purpose.

IgE hyperproduction through enhanced tyrosine phosphorylation of Janus kinase 3 in NC/Nga mice, a model for human atopic dermatitis

IgE hyperproduction frequently observed in patients with atopic dermatitis (AD) may greatly contribute to the pathogenesis of AD, but its mechanisms are still unclear. NC/Nga mice raised in nonsterile circumstances spontaneously suffered from AD-like skin lesions with elevation of plasma IgE levels. We investigated mechanisms of the IgE hyperproduction in NC/Nga mice. Splenic T cells from SPF NC/Nga mice had a level of CD40 ligand (CD40L) expression comparable to that of BALB/c mice. Although there was no difference in the expression of CD40 on B cells between NC/Nga and BALB/c mice, B cells of NC/Nga mice produced much more IgE in the presence of soluble CD40L and IL-4. The stimulation with CD40L and/or IL-4 resulted in tyrosine phosphorylation of Janus kinase 3 (JAK3) in B cells, which was more strongly inducible in NC/Nga mice than in BALB/c mice. In B cells isolated from PBMC of AD patients with high serum IgE levels, JAK3 was constitutively phosphorylated at the tyrosine residue, and its phosphorylation was enhanced by the treatment with CD40L and/or IL-4 as was that in splenic B cells of NC/Nga mice with dermatitis and high IgE levels. Thus, it is suggested that constitutive and enhanced JAK3 phosphorylation in B cells highly sensitive to CD40L and IL-4 may be attributable to IgE hyperproduction in NC/Nga mice and patients with AD.

[Study of preoperative combination therapy with UFT + CDDP in patients with gastric and colorectal cancer--concomitant effects based on the thymidylate synthase inhibitory rat]

The subjects were 39 patients with gastric cancer and 44 patients with colorectal cancer divided into a group administered 400 mg/day of UFT orally for 2 weeks preoperatively (UFT group) and a group administered 400 mg/day of UFT as well as 40 mg/m2 (i.v.) of cisplatin (CDDP) by drip infusion once concomitantly (UFT + CDDP group). The thymidylate synthase (TS) inhibitory rate was measured in resected specimens and lymph nodes, and the concomitant effects of UFT and CDDP were investigated.

RESULTS

1) The TS inhibitory rate in tumor tissue showed no significant difference between the two groups. 2) The TS inhibitory rate of metastasized lymph nodes was higher in UFT + CDDP group than in the UFT group in gastric cancer patients (p < 0.05). The TS inhibitory rate by lymph node metastasis in patients with gastric cancer or colorectal cancer was significantly higher in metastasized lymph nodes than in non-metastasized lymph nodes in the UFT + CDDP group (p < 0.05 for gastric cancer, p < 0.05 for colorectal cancer). These results indicated that concomitant use of UFT and CDDP appeared to be more effective against metastasized lymph nodes, especially in cases of gastric cancer, than against the primary tumor focus.

[UFT/CDDP preoperative chemotherapy for progressive gastric cancer--histological antitumor effects and thymidylate synthase inhibition rate]

Pre-operative chemotherapy with concomitant use of UFT and CDDP (UFT: oral administration of 400 mg/day for 2 weeks till one day before operation, CDDP, one intravenous drip of 40 mg/m2 one week before operation) was used for 24 untreated cases of advanced stomach cancer diagnosed as resectable pre-operatively, and the histological antitumor effect analyzed in dissected preparation and the thymidylate synthase inhibition rate (TSIR: %) in tumor tissue were examined. The average administration dose of CDDP was 61.1 mg/body, and the average total administration dose of UFT was 5.0 g/body. The histological antitumor effect was grade 0 in 8 cases (33.3%), grade 1a in 10 cases (41.7%), grade 1b in 5 cases (20.8%), and grade 2 in 1 case (4.2%). TSIR in tumor tissue was under 10% in 2 cases (9.1%); over 10% and under 20% in 4 cases (18.2 %); over 20% and under 30% in 6 cases (27.3%); over 30% and under 40% in 5 cases (22.7%); over 40% and under 50% in 3 cases (13.6%); over 50 % in 2 cases (9.1%), and not measurable in 2 cases, with the average of 29.0%. The correlation was observed between histological anti-tumor effect and TSIR in tumor tissue (p < 0.05). These results suggest the possibility that the anti-tumor effect can be estimated at the in vivo level from measurement of TSIR in tumor tissue.

beta,beta'-Iminodipropionitrile toxicity in normal and congenitally neurofilament-deficient Japanese quails

Morphological effects of a neurotoxin, beta,beta'-iminodipropionitrile (IDPN) were analyzed in normal and congenitally neurofilament (NF)-deficient Japanese quails. These quails (6 weeks old) were injected intraperitoneally with IDPN (0.2 g/kg body weight) three times every 3 days. They were necropsied at 10 to 12 days after the first injection. In normal quails, axonal swellings were observed histologically in the ventral motoneurons, ventral root, commissura grisea and spinal ganglion in the cervical and synsacral spinal cord. Electron microscopically, the changes consisted of increased NFs, with scattered mitochondria, smooth endoplasmic reticulum and microtubules. The myelin sheaths of the involved nerves were thinner than those of the normal axons. These lesions were similar to those induced by IDPN intoxication in mammalian experimental animals. In NF-deficient quails injected with IDPN, no axonal changes were detected. These findings suggested that IDPN selectively attacked the NFs.