Influence of changing various parameters in miniscrew-assisted rapid palatal expansion: A three-dimensional finite element analysis / 대한치과교정학회지

OBJECTIVE@#This study aimed to analyze the effect of changing various parameters of the bone-borne rapid palatal expander (RPE) using the finite element method (FEM).@*METHODS@#In eight experimental groups, we investigated the effect of the number, position, and length of miniscrews; positional changes of the expander; and changes in the hook length on maxillary expansion. In finite element analysis, we compared the magnitude and distribution of stress, and the displacement changes following expansion of the bone-borne RPE.@*RESULTS@#When we compared the number and position of miniscrews, placing miniscrews in the anterior and posterior sides was advantageous for maxillary expansion in terms of stress distribution and displacement changes. Miniscrew length did not significantly affect stress distribution and displacement changes. Furthermore, anteroposterior displacement of the expander did not significantly affect transverse maxillary expansion but had various effects on vertical changes of the maxilla. The maxilla rotated clockwise when the miniscrews were placed in the anterior region. The hook length of the expander did not show consistent results in terms of changes in stress distribution and magnitude or in displacement changes.@*CONCLUSIONS@#The findings of this study suggest that changes in the location and length of the miniscrews and displacement of the bone-borne RPE could affect the pattern of the maxillary expansion, depending on the combination of these factors.

Nitric Oxide Synthase Expression and Apoptosis in Psoriasis / 대한피부과학회지

BACKGROUND: Nitric oxide(NO) is generated from L-arginine by NO synthase(NOS). Three types of NOS are currently known:inducible(iNOS), neuronal(nNOS) and endothelial(eNOS). NO has been found to be important in a number of different physiological processes. Of particular relevance to the skin are the roles of NO in vasodilatation, inflammation, immunomodulation and in oxidative damage to cells and tissues. NO exhibits contradictory effects in the regulation of apoptosis. The proapoptotic effects seem to be linked to pathophysiological conditions, where high amounts of NO are produced by iNOS. In contrast, the continuous release of eNOS inhibits apoptosis. Psoriasis is a common chronic skin disease, but the cause of psoriasis is not definitely known until now. OBJECTIVE: To investigate the role of NO in psoriasis pathogenesis, such as inflammatory infiltration, dermal vessels dilatation, apoptosis, we performed this study. METHODS: Ten cases of psoriasis and 5 cases of normal skin for immunohistochemical with antibodies to iNOS, PCNA, bcl-2, p53 and TUNEL stainings, and 5 cases of psoriasis and 2 cases of normal skin for western blot with antibody to iNOS were investigated. RESULTS: The results were summarized as follows.1. Immunohistochemical staining with iNOS showed positive reactions in 9 cases(90 %) of psoriasis, 4 cases among them were strong positive staining, but all cases of normal skin were negative.2. Labelling index of PCNA staining was 24.4+2.5%, 2.4+0.7% in psoriasis, normal skin, respectively.3. All cases of psoriasis and normal skin were negative in p53 staining, but squamous cell carcinoma as positive control was positive.4. Bcl-2 staining showed focal positivity in 5(50%) cases of psoriasis, but diffuse positivity in epidermal basal layer of normal skin.5. TUNEL staining showed positivity in 7(70%) cases of psoriasis, but all of normal skin were negative.6. Western blot with anti-iNOS showed positive 130 kDa band in psoriatic, but not in normal skin tissues. CONCLUSION: The results suggested that NO was considered to play a role in psoriasis pathogenesis, including apoptosis, dermal vessels dilatation and inflammatory infiltration.

A Case of Nodular Amyloidosis

A 38-year-old male patient visited our clinic complaining of three skin lesions on the scalp. There were yellowish to brownish, waxy, non-tender, walnut-sized nodules. Hematoxylin and eosin staining revealed amorphous pinkish material deposits in the dermis. The Congo red stain and Dylon stain under polarizing microscopy showed yellow-green birefringence and the immunoglobulin-lambda light chain stain showed a positive reaction. An electron microscopic examination revealed filaments with uniform diameter(6 to 10nm) that were straight and neither branched nor anastomosed. Based on the clinical, histopathological, immunohistochemical and electron microscopical findings, the skin lesions were diagnosed as nodular amyloidosis.

A Case of Woolly Hair

We report a case of woolly hair. Woolly hair is found frequently in most blacks but is unusual in individuals of non-negroid origin. A 12-year-old female patient visited our clinic complaining of a hair abnormality. It had been tightly curled, fine, light brown, short and easily broken since birth. On scanning electron microscopy, many of the hairs showed damaged cuticles with cuticular splintering, and most hair shafts were round to oval on cross sectional examination.

Cutaneous Manifestations in Sepsis Caused by Methicillin-Resistant Staphylococcus aureus / 대한피부과학회지

Sepsis refers to the systemic response to serious infection. Patients with sepsis usually manifest fever, tachycardia, tachypnea, leukocytosis, and a localized site of infection. Methicillin-resistant Staphylococcus aureus(MRSA) is a gram-positive, nonmotile, aerobic, catalase- positive coccus, which is resistant to all the B -lactam antibiotics. Cutaneous manifestations in sepsis are maculopapules, nodules, petechiae, ecchymoses, purpurae, pustules, vesiculobullae, hemorrhagic bullae and ulcers. When MRSA is identified in blood cultures and skin tissue cultures, the skin lesions can be considered as cutaneous manifestations in sepsis caused by MRSA. We report two cases with erythematous pustules, petechiae, hemorrhagic bullae and maculopapules caused by MRSA sepsis. MRSA grew in blood cultures and skin tissue cultures.