A 5-kV pulse generator with a 100-kV/µs slew rate based on series-connected 1700-V SiC MOSFETs for electrical insulation tests

This study demonstrates a high-slew-rate 5-kV pulse generator for electrical insulation tests. Electrical equipment, such as electrical actuators and traction drive motors, are exposed to severe electrical stress because recent switching inverters have high-frequency outputs with high supply voltages using wide-bandgap power devices. For an advanced electrical insulation test, a high-voltage pulse generator is required with a high slew rate; however, such generators suffer from large switching noise, followed by measurement noise, such as ground voltage fluctuations and radiation noise, hindering the detection of partial discharge (PD) phenomena. In this study, we propose a 5-kV pulse generator based on series-connected 1700-V silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs). Four 1700-V SiC MOSFETs are connected in series as a 5-kV SiC switching module, constituting a half-bridge configuration for the pulse generator. The obtained switching waveforms exhibit fast rise times of 48 ns under 5 kV and 6.2 ns under 400 V with a low voltage overshoot and ringing owing to superior device characteristics and reduced parasitic inductances. Because of the low switching noise, we detect a clear PD signal with a 1500-V pulse when using the fabricated pulse generator for a PD test of a twisted pair. The proposed pulse generator uses a hard switching configuration such that the pulse generator can vary the pulse width from 150 ns to DC and increase the switching pulse cycle beyond 1 MHz by changing the control signals of the SiC MOSFETs.

Nuclear resonant scattering measurements on (57)Fe by multichannel scaling with a 64-pixel silicon avalanche photodiode linear-array detector

We developed a silicon avalanche photodiode (Si-APD) linear-array detector for use in nuclear resonant scattering experiments using synchrotron X-rays. The Si-APD linear array consists of 64 pixels (pixel size: 100 × 200 μm(2)) with a pixel pitch of 150 μm and depletion depth of 10 μm. An ultrafast frontend circuit allows the X-ray detector to obtain a high output rate of >10(7) cps per pixel. High-performance integrated circuits achieve multichannel scaling over 1024 continuous time bins with a 1 ns resolution for each pixel without dead time. The multichannel scaling method enabled us to record a time spectrum of the 14.4 keV nuclear radiation at each pixel with a time resolution of 1.4 ns (FWHM). This method was successfully applied to nuclear forward scattering and nuclear small-angle scattering on (57)Fe.

Localized Cutis Marmorata Telangiectatica Congenita on the Back of a Young Man

We report the clinical and light microscopic features of a case of cutis marmorata telangiectatica congenita with a painful refractory ulcer that was found on the back of a young Japanese man. The ulcer was positioned on the upper back over the spinal bone. In addition to the anatomical location of the ulcer, the vascular ectases may have played a part in the refractory ulceration.

Erythema Nodosum Induced by the Synergism of Acupuncture Therapy and Flu-Like Infection

A 32-year-old female patient developed erythema nodosum-like lesions at needle prick sites after acupuncture therapy. Over the next few days, she developed similar new lesions over the extremities, trunk and face along with flu-like symptoms. There were neither genital ulcerations nor eye lesions. A skin biopsy specimen from an extremity lesion showed the characteristic findings of erythema nodosum. Treatment with oral potassium iodide at a dose of 750 mg/day was effective, and there has not been any recurrence to date. We diagnosed this case as erythema nodosum induced by a synergism between acupuncture therapy and a flu-like infection.

Characteristics of Skin Surface Morphology and Transepidermal Water Loss in Clinically Normal-Appearing Skin of Patients with Atopic Dermatitis: A Video-Microscopy Study

In patients with atopic dermatitis (AD), it is debatable whether clinically normal-appearing skin is equal to non-atopic normal skin. The aim of this study was to quantitatively evaluate the characteristics of normal-appearing skin of AD. We examined the value of skin surface morphological changes using a new, simple, computer-assisted method with a video microscope. We also investigated the physiological function as represented by transepidermal water loss (TEWL) levels in 44 patients with AD and 15 normal controls. The morphological changes were represented by a variation coefficient score that reflected the irregularity of skin ridges, named the surface irregularity index (SII). There were significant differences between the normal-appearing skin of AD and non-atopic normal skin in both SII (P<0.001) and in TEWL (P<0.01). Especially for the SII, there were significant differences between AD subgroups subdivided by peripheral blood eosinophil count (Eo), serum lactate dehydrogenase level, and clinical score. TEWL values were significantly higher in the high-Eo AD group (n=15) than in the low-Eo AD group (n=29) (P<0.05). These findings indicate that clinically normal-appearing skin of AD patients with high disease activity differs from non-atopic normal skin in both surface morphology and physiology and that these changes reflect the current disease activity.

Peripheral choline acetyltransferase in rat skin demonstrated by immunohistochemistry

Conventional choline acetyltransferase immunohistochemistry has been used widely for visualizing central cholinergic neurons and fibers but not often for labeling peripheral structures, probably because of their poor staining. The recent identification of the peripheral type of choline acetyltransferase (pChAT) has enabled the clear immunohistochemical detection of many known peripheral cholinergic elements. Here, we report the presence of pChAT-immunoreactive nerve fibers in rat skin. Intensely stained nerve fibers were distributed in association with eccrine sweat glands, blood vessels, hair follicles and portions just beneath the epidermis. These results suggest that pChAT-positive nerves participate in the sympathetic cholinergic innervation of eccrine sweat glands. Moreover, pChAT also appears to play a role in cutaneous sensory nerve endings. These findings are supported by the presence of many pChAT-positive neuronal cells in the sympathetic ganglion and dorsal root ganglion. Thus, pChAT immunohistochemistry should provide a novel and unique tool for studying cholinergic nerves in the skin.

Topical application of ex vivo expanded endothelial progenitor cells promotes vascularisation and wound healing in diabetic mice

Impaired wound healing leading to skin ulceration is a serious complication of diabetes and may be caused by defective angiogenesis. Endothelial progenitor cells (EPCs) can augment neovascularisation in the ischaemic tissue. Experiments were performed to test the hypothesis that locally administered EPCs can promote wound healing in diabetes. Full-thickness skin wounds were created on the dorsum of diabetic mice. EPCs were obtained from bone marrow mononuclear cells (BMMNCs) and applied topically to the wound immediately after surgery. Vehicle and non-selective BMMNCs were used as controls. Wound size was measured on days 5, 10 and 14 after treatment, followed by resection, histological analysis and quantification of vascularity. Topical application of EPCs significantly promoted wound healing, as assessed by closure rate and wound vascularity. Immunostaining revealed that transplanted EPCs induced increased expression of vascular endothelial growth factor and basic fibroblast growth factor. Few EPCs were observed in the neovasculature based on in vivo staining of the functional vasculature. Ex vivo expanded EPCs promote wound healing in diabetic mice via mechanisms involving increased local cytokine expression and enhanced neovascularisation of the wound. This strategy exploiting the therapeutic capacity of autologously derived EPCs may be a novel approach to skin repair in diabetes.

Increased plasma LIGHT levels in patients with atopic dermatitis

LIGHT [the name of which is derived from 'homologous to lymphotoxins, exhibits inducible expression, competes with herpes simplex virus glycoprotein D for herpes simplex virus entry mediator (HVEM), and expressed by T lymphocytes'], is a member of the tumour necrosis factor superfamily that is involved in various inflammatory diseases. We aimed to estimate the relevance of plasma LIGHT levels as a biomarker for atopic dermatitis (AD). In order to understand the putative role of LIGHT in AD pathogenesis, we also investigate the effects of LIGHT on a monocytic cell line, human acute monocytic leukaemia cell line (THP-1). We examined plasma LIGHT levels, total serum IgE, serum value of CCL17 and peripheral blood eosinophil counts in patients with AD and healthy subjects. The effects of LIGHT on activation and apoptosis in THP-1 cells were also investigated. The plasma concentrations of LIGHT in AD patients were significantly higher than those in healthy individuals and the concentrations decreased as the symptoms were improved by treatment. The LIGHT plasma concentrations correlated with IgE levels and the Severity Scoring of AD (SCORAD) index. In addition, LIGHT stimulation increased expression of CD86 and induced production of interleukin-1β in THP-1 cells. Apoptosis was inhibited, the Bcl-2 level increased and the caspase-3 level decreased in THP-1 cells stimulated with LIGHT, compared to unstimulated control cells. These results suggest that plasma LIGHT levels may be one of the promising biomarkers for AD.

CXCR4 antagonist AMD3100 accelerates impaired wound healing in diabetic mice

The antagonism of CXC-chemokine receptor 4 (CXCR4) with AMD3100 improves cardiac performance after myocardial infarction by augmenting the recruitment of endothelial progenitor cells (EPCs) from the bone marrow to the regenerating vasculature. We investigated whether AMD3100 may accelerate diabetes-impaired wound healing through a similar mechanism. Skin wounds were made on the backs of leptin-receptor–deficient mice and treated with AMD3100 or saline. Fourteen days after treatment, wound closure was significantly more complete in AMD3100-treated mice (AMD3100: 87.0±2.6%, Saline: 33.1±1.8%; P<0.0001) and was accompanied by greater collagen-fiber formation, capillary density, smooth-muscle-containing vessel density, and monocyte/macrophage infiltration. On day 7 after treatment, AMD3100 was associated with higher circulating EPC and macrophage counts and with significantly upregulated mRNA levels of stromal-cell–derived factor 1 and platelet-derived growth-factor B in the wound bed. AMD3100 also promoted macrophage proliferation and phagocytosis and the migration and proliferation of diabetic mouse primary dermal fibroblasts and 3T3 fibroblasts, which express very little CXCR4. In conclusion, a single topical application of AMD3100 promoted wound healing in diabetic mice by increasing cytokine production, mobilizing bone-marrow EPCs, and enhancing the activity of fibroblasts and monocytes/macrophages, thereby increasing both angiogenesis and vasculogenesis. Not all of the AMD3100-mediated effects evolved through CXCR4 antagonism.

Granuloma annulare-like reaction to the bacillus Calmette-Guerin vaccination

We report the case of a 6-month-old girl with a granuloma annulare (GA)-like reaction to the bacillus Calmette-Guerin (BCG) vaccination. The eruption developed at the vaccination site 1 month after vaccination and the lesion gradually disseminated over the body within 2 months. A biopsy specimen of the skin lesion showed degenerated collagen bundles surrounded by imperfect palisading histiocytes, lymphocytes and epithelioid cells in the dermis, which led to a diagnosis of GA-like reaction as a secondary reaction to BCG inoculation. The eruption at the vaccination site and the scattered GA reaction resolved after 1 month of treatment with prednisolone valerate acetate ointment, leaving only pigmentation.

Anteriorly based pericranial flap: an anatomic study of feeding arteries

The purpose of this study was to obtain anatomic data on the branching levels of the deep branches of the supraorbital artery (SoA) and of the supratrochlear artery (StA) in pericranial flaps. Ten preserved cadavers were used for this study. Each vessel was identified on 12 sides. The deep branch of the SoA had a larger caliber than that of the StA in seven of nine sides. The branching level of the deep branch of the SoA was cephalad to that of the StA on six of nine sides. The deep branch of the SoA diverged shortly after emerging from the supraorbital foramen or notch. However, there were a few cases in which the branch originated at a distance of a few millimeters before or after the foramen or notch. From a practical standpoint, dissection of this pericranial flap below the level of the supraorbital ridge is not advised, and preservation of both feeding arteries is encouraged in order to establish abundant vascularity for this flap.

Early depth assessment of local burns by videomicroscopy: 24 h after injury is a critical time point

PURPOSE

Videomicroscopy has simple and prompt operability, and useful in the burn depth assessment in its early phase. A burn wound is, however, a dynamic environment in the first few days and the critical time to assess a burn wound by videomicroscopy has not been investigated. The aim of this study is to investigate the critical time point to assess the burn depth by videomicroscopy.

METHODS

Forty one patients with 44 intermediate depth burns admitted within 7 days after injury were included. Accuracies were assessed by comparison with clinical outcome: healing within 21 days after injury or not with conservative treatment. We prospectively evaluated and compared the accuracy of the videomicroscopy measurements with the clinical assessments. All findings were serialized in order of time after injury and divided into three groups, and we compared the appreciation of burn depth by videomicroscopy findings among groups.

RESULTS

The videomicroscopy measurements is significantly accurate compared with clinical assessments (p=0.001). The accuracy of videomicroscopy measurements was significantly lower in the post-injury <24 h group compared with post-injury ≥24 h group (p=0.004).

CONCLUSION

Videomicroscopy is effective tool in assessment of early burn depth and the critical time point to assess the burn depth by videomicroscopy is 24 h after injury.

Development of a pattern to measure multiscale deformation and strain distribution via in situ FE-SEM observations

We investigated a method for measuring deformation and strain distribution in a multiscale range from nanometers to millimeters via in situ FE-SEM observations. A multiscale pattern composed of a grid as well as random and nanocluster patterns was developed to measure the localized deformation at the specimen surface. Our in situ observations of a carbon fiber-reinforced polymer matrix composite with a hierarchical microstructure subjected to loading were conducted to identify local deformation behaviors at various boundaries. We measured and analyzed the multiscale deformation and strain localizations during various stages of loading.

Persistent congenital milia involving the skin of the whole body in an infant with trisomy 13 syndrome

Milia are tiny pearly-white cysts on the surface of the skin. In newborns, milia are usually located around the nose and eyes and generally disappear after the first several weeks of life. Trisomy 13 is a severe chromosomal disorder, with various complications. Here, we report a case of a 9-month-old female infant with trisomy 13 who had persistent congenital milia covering her entire body surface.

Double cancer of plantar malignant melanoma and vulvar extramammary Paget's disease

A 75-year-old woman presented with a 2-year history of a pigmented nodular lesion on her left sole and a 9-year history of a red infiltrative plaque on the vulva. The plantar lesion was a 15-mm ulcerated nodule located at the center of a 25-mm atypical pigmentation region; the nodule was clinically suspected to be a malignant melanoma. Histopathological analysis of the vulvar lesion biopsy sample indicated extramammary Paget's disease (EMPD). There was no evidence of metastasis in the computed tomography (CT) and (18)F-fluorodeoxyglucose positron emission tomography scans. We simultaneously performed a wide excision of both lesions and a left inguinal sentinel lymph node biopsy. Melanoma cells were identified in the sentinel lymph nodes, and left radical lymph node dissection was performed after a course of neoadjuvant chemotherapy. All the lymph nodes that were resected during the second operation tested negative for melanomas, and the plantar lesion was diagnosed as a stage IIIB malignant melanoma (pT4b, Na2, M0). Thereafter, we administrated four courses of chemotherapy, and 8 months after the operation, there was no evidence of recurrence or metastatic lesions. We present a case report of double cancer: a plantar malignant melanoma and vulvar EMPD, and also discuss the possible genetic mutations responsible for these two tumors.

Psoriasiform skin lesion and supprative acrodermatitis associated with Kawasaki disease followed by the treatment with infliximab: a case report

A 4-month-old boy was diagnosed with Kawasaki disease. The ordinary treatments with intravenous gammaglobulin and metylpredonisolone were not effective. Infliximab (5 mg/kg) was administrated on 13th day of illness which led to defeverscence and improvement of clinical manifestations. On 23 days of illness, however, desquamative papules and plaques developed on both the extensor surfaces of the forearms and legs. In addition, typical subungual desquamations of fingers and toes followed crusted hyperkeratosis which resembled supprative acrodermatitis. Skin biopsy from the forearm showed inflammatory dyskeratosis with marked hyperkeratosis, epithelial parakeratotsis, loss of granular layer and dominant infiltration of CD8 + T-cells. Local treatment of steroid followed improvement of skin lesions within a few weeks.

CONCLUSION

Although previous reports described the beneficial effects of infliximab in patients with Kawasaki disease, it is possible that the administration of infliximab modify psoriasiform skin lesion associated with Kawasaki disease.

Change in carrier type in high-k gate carbon nanotube field-effect transistors by interface fixed charges

We study the phenomenon of change in carrier type in carbon nanotube field-effect transistors (CNFETs) caused by the atomic layer deposition (ALD) of a HfO(2) gate insulator. When a HfO(2) layer is deposited on a CNFET, the type of carrier changes from p-type to n-type. The so-obtained n-type device has good performance and stability in air. The conductivity of such a device with a channel length of 0.7 microm is 11% of the quantum conductance 4e(2)/h. The contact resistance for electron current is estimated to be 14 kOmega. The n-type conduction of this CNFET is maintained for more than 100 days. The change in carrier type is attributed to positive fixed charges introduced at the interface between the HfO(2) and SiO(2) layers. We also propose a novel technique to control the type of conduction by utilizing interface fixed charges; this technique is compatible with Si CMOS process technology.

Mitf silencing cooperates with IL-12 gene transfer to inhibit melanoma in mice

Malignant melanoma is a malignant neoplasm originating from the melanocyte lineage. Microphthalmia-associated transcription factor (Mitf) is crucially involved in the melanin synthesis as well as proliferation and survival of melanocyte and melanoma. We previously showed that short interfering RNA (siRNA) that is specific for the Mitf gene (Mitf-siRNA) significantly inhibited growth of B16 melanoma after electro-transfected in vivo into preestablished tumor in mice. Here we assessed efficacy of electroporation-mediated co-transfection of Mitf-siRNA and IL-12 gene in the treatment of murine melanoma. As results, the tumor growth was more strongly inhibited by intratumor co-transfection with Mitf-siRNA and IL-12-encoding plasmid DNA than by transfection with either of the molecules alone. The co-transfection induced intratumor infiltration of CD4+ and CD8+ T cells, and hampered neoangiogenesis in the tumor. The findings suggest that the RNAi/cytokine gene combination therapy by means of electroporation may become a novel and efficacious therapeutic modality to treat neoplasms including melanoma.

Platelet activation in patients with psoriasis: increased plasma levels of platelet-derived microparticles and soluble P-selectin

BACKGROUND

It has recently been established that platelets have an important role in increasing inflammation, in addition to their main role in hemostasis and thrombosis. An increased incidence of occlusive vascular disease has been reported in patients with psoriasis and the pathomechanism of psoriasis may involve platelet activation.

OBJECTIVE

The goal of the study was to establish a clearer explanation of the association between platelet activation and psoriasis activity by investigating the levels of markers of platelet activation in patients with psoriasis and examining the relationship between the marker levels and a severity score for psoriasis.

METHODS

Plasma levels of platelet-derived microparticles (PDMPs) and soluble P-selectin were measured by enzyme-linked immunosorbent assay as markers of platelet activation in 21 patients with psoriasis and 22 healthy control subjects. The relationships between the platelet activation markers and the Psoriasis Area and Severity Index score were investigated.

RESULTS

Plasma PDMPs and soluble P-selectin levels were markedly higher in patients with psoriasis compared with those in healthy control subjects. There was a significant correlation between the PDMPs levels and the Psoriasis Area and Severity Index score, and the increased plasma PDMPs and soluble P-selectin levels were markedly reduced after clinical improvement occurred.

LIMITATIONS

The number of people evaluated was relatively small.

CONCLUSIONS

Our results show that blood platelets are activated in patients with psoriasis, especially in those with extensive disease, and suggest a close association between platelet activation and psoriasis activity. Plasma PDMPs level may be a useful indicator of the severity of psoriasis.

Case of autoimmune progesterone dermatitis presenting as fixed drug eruption

Autoimmune progesterone dermatitis is a rare disorder that presents as a cyclical cutaneous eruption during the luteal phase of the menstrual cycle. It typically occurs in women due to an autoimmune phenomenon to endogenous progesterone production. We describe a 34-year-old woman with an erythematous round plaque with blistering, which recurred a few days before her menstrual cycle, at the identical site on the left arm. The diagnosis of autoimmune progesterone dermatitis is made with i.d. skin testing on the affected lesion with progesterone. After the beginning of oral prednisolone (40 mg daily) therapy during menstruation, although slight recurrence appeared, the severity was significantly improved.

Successful treatment of Stevens-Johnson syndrome with steroid pulse therapy at disease onset

PURPOSE

To evaluate the visual prognosis of patients with Stevens-Johnson syndrome (SJS) and its severe variant, toxic epidermal necrolysis (TEN), followed by general and topical high-dose corticosteroids administration from disease onset.

DESIGN

Prospective, observational case series.

METHODS

Between May 1, 2003 and June 30, 2005, we enrolled 5 patients with SJS or TEN with ocular complications at the acute stage. Intravenous pulse therapy with methylprednisolone (steroid pulse therapy; 500 or 1000 mg/day for 3 to 4 days) was initiated within 4 days from disease onset. Topically, 0.1% betamethasone was applied over 5 times daily for at least 2 weeks. Visual acuity (VA) and slit-lamp microscopic appearance 1 year from disease onset were evaluated.

RESULTS

At the first examination, corneal or conjunctival epithelial defects and pseudomembranous conjunctivitis were present in all cases. Skin eruptions dramatically improved after steroid pulse therapy. Although ocular inflammation increased for several days, pseudomembranes disappeared and corneal and conjunctival epithelium regenerated within 6 weeks. At the chronic stage, all eyes had clear corneas with the palisades of Vogt (POV), implying the presence of corneal epithelial stem cells. Best-corrected VA was 20/20 or better in all eyes. Five eyes showed superficial punctate keratopathy. No eye had cicatricial changes except for 1 with slight fornix shortening. No significant adverse effects of steroid occurred during all clinical courses.

CONCLUSIONS

Steroid pulse therapy at disease onset is of great therapeutic importance in preventing ocular complications. Topical betamethasone also shows great promise for preventing corneal epithelial stem cell loss in the limbal region and cicatricial changes.

Keratinocyte growth inhibition through the modification of Wnt signaling by androgen in balding dermal papilla cells

CONTEXT/OBJECTIVE

Androgen induces androgenetic alopecia (AGA), which has a regressive effect on hair growth from the frontal region of the scalp. Conversely, Wnt proteins are known to positively affect mammalian hair growth. We hypothesized that androgen reduces hair growth via an interaction with the Wnt signaling system. The objective of this study was to investigate the effect of androgen on Wnt signaling in dermal papilla (DP) cells.

DESIGN

The effect of androgen and Wnt3a on keratinocyte proliferation was measured by use of a coculture system consisting of DP cells and keratinocytes. The molecular mechanisms of androgen and Wnt pathway interactions in DP cells were examined by analyzing the expression, intracellular localization, and activity of the androgen receptor (AR) and also downstream Wnt signaling molecules.

RESULTS

Wnt3a-dependent keratinocyte growth was suppressed by the addition of dihydrotestosterone in coculture with DP cells that were derived from AGA patients, but growth was not suppressed in coculture with DP cells from non-AGA males. Whereas DP cells from both scalp regions expressed AR protein, the expression levels of AR and cotranslocation with beta-catenin, a downstream Wnt signaling molecule, were higher in DP cells of AGA patients than in DP cells from non-AGA males. In addition, significant suppression of Wnt signal-mediated transcription in response to dihydrotestosterone treatment was observed only in DP cells from AGA patients.

CONCLUSION

These results suggest that Wnt signaling in DP cells is regulated by androgen and this regulation plays a pivotal role in androgen's action on hair growth.