Search

Aggregation is a major problem for hydrophobic carbon nanomaterials such as carbon nanotubes (CNTs) in water because it reduces the effective particle concentration, prevents particles from entering the medium, and leads to unstable electronic device performances when a colloidal solution is used. Molecular ligands such as surfactants can help the particles to disperse, but they tend to degrade the electrical properties of CNTs. Therefore, self-dispersed particles without the need for surfactant are highly desirable. We report here, for the first time to our knowledge, that CNT particles with negatively charged hydrophobic/water interfaces can easily self-disperse themselves in water via pretreating the nanotubes with a salt solution with a low concentration of sodium hypochlorite (NaClO) and sodium bromide (NaBr). The obtained aqueous CNT suspensions exhibit stable and superior colloidal performances. A series of pH titration experiments confirmed the presence and role of the electrical double layers on the surface of the salted carbon nanotubes and of functional groups and provided an in-depth understanding of the phenomenon. [ABSTRACT FROM AUTHOR]

The article presents the clinical case of a 22-year-old man diagnosed with a mass in the right lower chest. Reportedly, the mass in the right lower chest had grown gradually and become painful over two years. The patient has undergone ultrasound examination, where a well-circumscribed homogeneous solid mass between the external oblique and external intercostal muscle was found. Furthermore, the clinical findings had revealed schwannoma or a hemangioma.

Loricrin is a major component of the epidermal cornified cell envelope, and is expressed only in terminally differentiated keratinocytes. This cell differentiation-specific expression pattern suggests specific suppression of loricrin gene expression in undifferentiated keratinocytes as well as its activation in differentiated keratinocytes. We identified a negative regulatory sequence element in the first intron of the mouse loricrin gene involved in suppression of loricrin gene expression in undifferentiated keratinocytes. A database search indicated that this sequence contained the putative inverted Yin-Yang 1 (YY1)-binding motif. Constructs with point mutations in the putative YY1-binding motif showed increased reporter activity, indicating that YY1 negatively regulates loricrin gene transcription. Co-transfection experiments using a YY1 expression vector revealed that YY1 represses loricrin promoter activity. Western blotting and immunohistochemical analyses indicated that YY1 is more abundant in undifferentiated than in differentiated keratinocytes. These findings suggest that YY1 contributes to specific loricrin gene expression in differentiated keratinocytes by suppression of its transcription in undifferentiated keratinocytes. Furthermore, we demonstrated that forced expression of YY1 in differentiated keratinocytes results in specific downregulation of expression of other early and late differentiation markers. [ABSTRACT FROM AUTHOR]

Previous studies of epidermal-specific gene promoters suggested that a limited set of transcription factors regulate keratinocyte-specific and differentiation-specific gene expression in the epidermis. In the present study, we investigated the functional importance of AP-1- and Sp1-binding elements in the determination of cell type-specific and differentiation-specific gene expression by transient transfection into undifferentiated and differentiated keratinocytes as well as into various non-epidermal cell lines. Synthesized short AP-1- and/or Sp1-binding elements were inserted into a minimal reporter vector, and the artificial promoter containing both AP-1 and Sp1 elements showed high levels of transcriptional activity only when transfected into differentiated keratinocytes. Promoters containing either the AP-1 or the Sp1 motif alone showed little activity in any of the cells examined. We also found that close proximity of the Sp1 and AP-1 sites is essential for transcriptional activity, suggesting that the physical interaction between Sp1 and AP-1 factors is important for functional activity. These results clearly demonstrate that the combination of ubiquitously expressed transcription factors AP-1 and Sp1 confers keratinocyte specificity and differentiation specificity on the gene expression. Our findings also provide a simple model of the mechanisms underlying regulation of cell type-specific and cell differentiation-specific gene expression by ubiquitously expressed transcription factors. [ABSTRACT FROM AUTHOR]

Background Reconstruction of vulvovaginal defects after tumor excision requires good-quality skin cover because of the cosmetic and functional importance of this region. Although numerous techniques for vulvovaginal reconstruction have been described, an ideal approach has yet to be widely accepted. Methods Seven gluteal-fold flaps advanced in a V-Y fashion were used to cover vulvovaginal defects in five patients who underwent surgical treatment for extramammary Paget's disease or carcinoma of the vulva. Results Each flap survived completely with no complication other than partial dehiscence in one case and temporary postoperative discomfort and pain upon sitting. None of the patients suffered from recurrence of the tumor. Conclusions In our experience, this flap is easily elevated, not bulky, and reliable because it is supplied by the internal pudendal artery and vein perforators without excessive skeletonization of the vascular pedicle, and it has matched local skin quality. In addition, it has minimal donor-site morbidity as the scar is concealed in the gluteal fold. It can cover medium-sized vulvovaginal defects after tumor excision. [ABSTRACT FROM AUTHOR]