Hwa-Young Park

A wireless vibrating wire sensor node for continuous structural health monitoring

Vibrating wire sensors (VWS) are generally used for strain measurements of structures in buildings and civil infrastructures. In this paper, a wireless vibrating wire sensor node is developed which can measure resonance frequencies from vibrating wire sensors and can remotely communicate the frequencies by wireless. The wireless sensor node consists of a sensor module, which excites the vibrating wire and reads the resonance frequencies, a wireless communication module, which transmits the wires resonance frequencies to the user or administrator, and a processor that controls the two modules. The wireless sensor node has the following characteristics: it has multiple channels to enable measurement of multiple vibrating wire sensors (up to four) using a single sensor node; it has a power-saving feature that enables operation for up to one year; and lastly, the wireless unit uses the 424 MHz UHF (ultra-high frequency) band with good diffraction that has an effect on minimizing the influence of impediments such as structural or nonstructural elements. The wireless sensor node is tested in terms of its measurement precision and its wireless communication performance. As a result, it is confirmed that the node enables the long-term structural health monitoring of buildings and infrastructures.

K6PC-5, a novel sphingosine kinase activator, improves long-term ultraviolet light-exposed aged murine skin.

Abstract:  Sphingosine‐1‐phosphate (S1P), which is formed by phosphorylation of sphingosine through a process catalysed by sphingosine kinase (SK), is a multifunctional mediator of a variety of cellular responses including proliferation, differentiation, motility, and survival. K6PC‐5, which was recently synthesized as a novel SK activator, is expected to increase S1P levels. Indeed studies have already demonstrated that K6PC‐5 exhibits anti‐aging effects on intrinsic aged murine skin by increasing fibroblasts, collagen synthesis, dermal thickness, and epidermal differentiation. However, photoaging and intrinsic aging have highly different clinical and histopathological properties. In this study, we developed a photoaged murine model by exposing mice that were 56 weeks old to ultraviolet (UV)B and UVA radiation for 8 weeks. We then investigated whether K6PC‐5, as an SK activator, had anti‐aging effects on photoaged murine skin in addition to its effects on intrinsic aged murine skin and determined the mechanism. K6PC‐5 increased dermal collagen density in photoaged skin through increases in fibroblasts and collagen production. Photoaged murine skin treated with K6PC‐5 showed an increase in stratum corneum (SC) integrity with increased corneodesmosome density and an improvement in barrier recovery rate. Matrix metalloproteinase 13 remained unchanged. These results indicate that topical application of K6PC‐5 improves photoaged skin by improving skin barrier and increasing fibroblast count and function. In conclusion, K6PC‐5, as an S1P activator, improves long‐term UV‐exposed aged skin as well as intrinsic aged skin.

Case of epidermolysis bullosa with pyloric atresia.

Epidermolysis bullosa (EB) is a rare hereditary disorder characterized by formation of blisters following minor trauma. It has been traditionally categorized by the level of basement membrane zone separation into EB simplex (EBS), junctional EB (JEB), and dystrophic EB (DEB). Recently, hemidesmosomal EB has been proposed as a fourth category, which includes EB with muscular dystrophy and EB with pyloric atresia. We report here on a case of concomitant occurrence of EB and pyloric atresia, a rare form of EB.

Anti-ageing effects of a new synthetic sphingolipid (K6EAA-L12) on aged murine skin.

Abstract:  Recently, we reported on the anti‐ageing effects of K6PC‐5. This compound induced keratinocyte differentiation and fibroblast proliferation by increasing sphingosine‐1 phosphate synthesis. We performed this study to confirm the anti‐ageing effects of new synthetic products (the K6EAA series) derived from K6PC‐5 through an amino group induction. Cellular responses such as differentiation, proliferation and calcium mobilization were investigated using cultured human keratinocytes and fibroblasts. Also, we measured the expressions of collagen mRNA and protein using real time RT‐PCR and ELISA, respectively. The K6EAA‐L12 product, selected by in vitro screening, was evaluated for anti‐ageing effects on intrinsically and extrinsically (photo) aged models of hairless mice. In the intrinsically aged murine skin, K6EAA‐L12 showed anti‐ageing effects by activating collagen synthesis, eventually causing dermal thickening. Also, in the photo‐aged skin, the dermal collagen density and dermal thickness were increased. In photo‐aged murine skin, K6EAA‐L12 increased stratum corneum integrity by increasing corneodesmosome density and improved the barrier recovery rate. However, there were no changes in the expressions of epidermal differentiation maker proteins. In conclusion, topical K6EAA‐L12, a new synthetic K6PC‐5 derivative, improves intrinsically and extrinsically (photo) aged skin by increasing the collagen density and improving the skin barrier function.

Antinuclear antibodies in patients with prurigo pigmentosa: a linkage or a coincidence?

Laboratory tests were within normal limits except for elevated ANA (1: 320, homogenous pattern), IgE ( 1 1,000 IU/ml) and eosinophil count (760 ! 10 6 /l). Other laboratory findings related to autoimmunity [anti-SS-A(Ro), anti-SS-A(La), ds-DNA antibodies] were negative. A skin biopsy showed marked spongiosis, exocytosis of neutrophils, blurring of dermoepidermal junctions, and superficial perivascular and interstitial lymphocytic infiltration ( fig. 2 a). Direct immunofluorescences (DIFs) were all negative. All of the features were consistent with PP. Daily treatment with 100 mg of doxycycline and 50 mg of dapsone was started. After 2 weeks, almost all of the lesions had been resolved leaving hyperpigmentation. The second patient was a 15-year-old female who presented with a 3-week history of a pruritic, erythematous eruption in the intermammary region and on the back ( fig. 1 b). She had been intermittently treated with topical corticosteroids for atopic dermatitis. Laboratory findings showed elevated ANA (1: 320, speckled pattern) and IgE (934 IU/ml). Additional laboratory findings related to autoimmunity [anti-SS-A(Ro), anti-SS-A(La), ds-DNA, anti-Sm antibodies] were negative. Histopathologic features showed intraepidermal blister, spongiosis, marked exocytosis, vacuolar alteration at the dermoepidermal junction and superficial perivascular lymphocytic infiltration ( fig. 2 b). DIFs were all negative. After the diagnosis of PP, treatment with 8 mg of methylprednisolone and 0.05% desonide lotion induced a dramatic response. The last patient was a 16-year-old female with a 3-week history of pruritic vesicular skin lesion on her back ( fig. 1 c). We performed a Tzanck smear from vesicular lesions, but it was negative. Laboratory findings showed elevated ANA (1: 80, homogenous pattern) and IgE (139 IU/ml), and other laboratory findings including autoimmunity [anti-SS-A(Ro), anti-SS-A(La), ds-DNA, anti-Sm antibodies] were within normal limits or negative. Histopathologic features were consistent with PP ( fig. 2 c), and DIFs were all negative. She was treated with 20 mg of prednisolone and

Cherry Angiomas on the Scalp

Cherry angiomas are a common cutaneous vascular proliferation which manifests as single or multiple spots and occurs predominantly on the upper trunk and arms. They typically appear as round-to-oval, bright, red, dome-shaped papules and pinpoint macules measuring up to several millimeters in diameter. The histopathologic findings of a cherry angioma are consistent with a true capillary hemangioma, which is formed by numerous, newly developed capillaries with narrow lumens and prominent endothelial cells arranged in a lobular fashion in the papillary dermis. Herein, we report a case of multiple cherry angiomas on the scalp, an uncommon location for cherry angiomas.

Nevus Sebaceous Accompanying Secondary Neoplasms and Unique Histopathologic Findings

Nevus sebaceous (NS) is a type of classical nevus or congenital malformation that is often present at birth and commonly involves the scalp or face. The lesion usually presents as a linear, yellow, hairless, and verrucous plaque. It has been well-established that several benign and malignant tumors can develop from the NS; however, there have been no reports about ectopic fat cells in the dermis, and cornoid lamella arising from the NS. We report a case of NS on the scalp with accompanying unusual histopathologic findings.

Periadnexal Mucin as an Additional Histopathologic Feature of Chronic Eczematous Dermatitis

Background Cutaneous mucinoses are a heterogeneous group of disorders characterized by an abnormal amount of mucin in the skin. However, the pathomechanism of an excessive mucin deposition in the skin is still unknown. Eczematous dermatitis is sub-classified histologically into acute, subacute, and chronic variants. The characteristic histopathologic findings for chronic eczema are variable. However, periadnexal mucin deposition is not known as a feature of chronic eczema. Objective To evaluate the presence of periadnexal mucin deposition in chronic eczematous dermatitis. Methods We analyzed the skin biopsy specimens from 36 patients who were pathologically diagnosed with chronic eczematous dermatitis. Alcian blue, colloidal iron, and periodic acid-Schiff stains were used to evaluate the mucin deposition in histologic sections. Two dermatologists and two dermatopathologists evaluated the degree of mucin deposition using a 4-point scale. Results Various amounts of mucin deposition were observed in the periadnexal area of patients who were diagnosed with chronic eczema. Mucin deposition was more visible after staining with mucin-specific stains. Evaluation of the staining analysis scores revealed that the staining intensities were significantly higher in patients with chronic eczema than age- and site-matched controls (normal, acute to subacute eczema, and psoriasis vulgaris). Conclusion Periadnexal mucin (secondary mucinoses) may be an additional finding of chronic eczematous dermatitis.

Variant of phacomatosis pigmentokeratotica

be clinically relevant. We have previously investigated the immunomodulatory effects of other antihistamines on keratinocytes. Cetirizine and levocetirizine are characterized by their strong suppressive abilities to IL-1a and CXCL8 production. Furthermore, levocetirizine has CD54-inhibitory and Th1 chemokine (CXCL11) and eosinophil chemokine (CCL5)inhibitory properties as seen in epinastine and bepotastine. These adhesion molecule and chemokines are involved in T-cell-mediated eczematous dermatitis. Levocetirizine is beneficial for the allergic skin diseases by virtue of not only its antihistaminic activity but also anti-allergic properties.

Concurrent Occurrence of Mucocele and Pyogenic Granuloma

A mucocele is a common, benign lesion of the oral cavity that develops following the extravasation or retention of mucous from a major or minor salivary gland. A pyogenic granuloma (PG) is also a common, benign condition characterized by proliferating capillaries that affect the skin and mucous membranes. The concurrent occurrence of a mucocele and a PG lesion has rarely been reported in the medical literature. This case study reports such a finding in a 16-year-old patient who presented to our department.