56 research outputs found

    Stability of Sb line structures on Si(001)

    Get PDF
    Structure and stability of Sb-dimer linear chains on the Si(001) surface are studied by means of ab initio quantum-mechanical molecular dynamics using pseudopotentials. It is confirmed that the model comprising a double core of seven-membered rings of silicon for Bi/Si(001) nanolines is indeed one of the most stable structures energetically, and it also explains Sb/Si nanolines. Moreover, it is clear that stability of the odd-membered-ring (5-7-5) structure will decrease as the group-V adatom changes from Bi to Sb, and disappear for As/Si due to the size effect

    Elastic fiber assembly is disrupted by excessive accumulation of chondroitin sulfate in the human dermal fibrotic disease, keloid

    Get PDF
    Keloid is a fibrotic disease characterized by abnormal accumulation of extracellular matrix in the dermis. The keloid matrix contains excess collagen and glycosaminoglycans (GAGs), but lacks elastic fiber. However, the roles of these matrix components in the pathogenesis of keloid are largely unknown. Here, we show that elastin and DANCE (also known as fibulin-5), a protein required for elastic fiber formation, are not deposited in the extracellular matrix of keloids, due to excess accumulation of chondoitin sulfate (CS), although the expression of elastin and DANCE is not affected. Amount of CS accumulated in the keloid legion was 6.9-fold higher than in normal skin. Fibrillin-1, a scaffold protein for elastic fiber assembly, was abnormally distributed in the keloid matrix. Addition of purified CS to keloid fibroblast culture resulted in abnormal deposition of fibrillin-1, concomitant with significantly decreased accumulation of elastin and DANCE in the extracellular matrix. We propose that CS plays a crucial role in the development of keloid lesions through inhibition of elastic fiber assembly

    Esophageal Squamous Cell Carcinoma with Marked Eosinophil Infiltration

    Get PDF
    We report a case of esophageal squamous cell carcinoma (SCC) with marked eosinophil infiltration which was identified postoperatively in the esophageal wall in areas not surrounding the SCC. The eosinophil infiltration was seen in the submucosa, muscle and adventitia, but not in the mucosa. Eosinophilic esophagitis (EoE) is a pathological condition defined as eosinophil infiltration within the esophageal mucosa. Eosinophil infiltration at the invasion front of esophageal SCC is termed tumor-associated tissue eosinophilia (TATE). However, the eosinophil infiltration in this case may be pathologically different from both EoE and TATE. To our knowledge, this is the first report of esophageal SCC with eosinophil infiltration

    Pneumatosis intestinalis with a benign clinical course: a report of two cases

    No full text
    Abstract Background Pneumatosis intestinalis (PI) is a rare condition characterized by the presence of gas within the gastrointestinal tract wall. Most cases of PI have a benign clinical course, although some have serious outcomes. Mechanical stress on or bacterial infection of the gastrointestinal tract wall may be responsible for the onset of PI, but the detailed mechanism of PI pathogenesis is still unclear. Here, we describe two Japanese patients presenting with benign PI. Case presentation Case 1, a 37-year-old previously healthy male patient, had a 1-week history of abdominal pain, and case 2, a 78-year-old female diabetic patient, had a 2-week history of voglibose treatment and abdominal pain. Intramural gas was mainly distributed in the colon in case 1 and in the small intestine in case 2. Interestingly, neither patient showed obvious inflammatory signs upon admission and recovered spontaneously with conservative treatment, including fasting and fluid infusion without antibiotics. Voglibose treatment was terminated in case 2. Recent studies have shown the presence of nonpathogenic bacteria, such as Clostridium spp., in PI lesions, which usually play an important role in modulating the tolerance of the gastrointestinal immune responses. The benign clinical course and spontaneous resolution of PI in these patients, without specific treatment, suggests that nonpathogenic indigenous bacteria in the gastrointestinal tract participate in the pathogenesis of PI. Conclusion In patients with benign PI, the absence of an inflammatory response and the spontaneous resolution of the disease without specific treatment suggest the participation of nonpathogenic indigenous bacteria of the gastrointestinal tract

    Immunoglobulin G4-Related Retroperitoneal Fibrosis Treated with Hochuekkito, a Kampo Medicine, following Steroid Treatment

    No full text
    We report a case of immunoglobulin G4 (IgG4)-related retroperitoneal fibrosis (RF) with complete remission and no relapses after therapy with steroids and Hochuekkito, a Kampo (i.e. traditional Japanese herbal) medicine. A 62-year-old Japanese man was admitted to our hospital for treatment of a retroperitoneal mass detected by computed tomography. The mass had a maximum diameter of 11.0 cm; it involved the left ureter and was associated with left hydronephrosis. After inserting a ureteral stent, we performed a biopsy by laparotomy. Histopathology revealed IgG4-related RF. The lesion disappeared after 7 months of steroid therapy. We subsequently used Hochuekkito as an alternative maintenance treatment because of steroid-related complications. The patient has not relapsed in the 3 years since starting the medication. To the best of our knowledge, this is the first case of IgG4-related RF treated with Hochuekkito as a maintenance treatment

    Regeneration of elastic fibers by three-dimensional culture on a collagen scaffold and the addition of latent TGF-β binding protein 4 to improve elastic matrix deposition.

    Get PDF
    The objective of this study was to investigate the effects of latent TGF-β binding protein 4 (LTBP-4) on elastic fiber regeneration in three-dimensional cultures of human dermal fibroblasts (HDFs). Appropriate collagen scaffold for elastic fiber regeneration was also examined. Collagen sponges cross-linked at 120 °C and composed of small pores (25 μm on average) was favorable for elastic fiber regeneration by HDFs. Addition of LTBP-4, followed by culture for 21 days, accelerated elastic fiber accumulation within the scaffolds. Conditioned scaffolds containing either HDFs or LTBP-4-built mature elastic fibers were implanted between the dermis and the cutaneous muscle of mice. The combined use of HDFs and LTBP-4 resulted in thicker tissues containing elastic fibers. These results indicate that weakly cross-linked collagen sponges can be used as scaffolds for regenerating elastic fibers both in vitro and in vivo, and that the addition of LTBP-4 accelerates the deposition of both elastin and fibrillin-1, and increases cell proliferation. These techniques may be useful for generating cutaneous or cardiovascular tissue equivalents; furthermore, they may serve as a useful method for the three-dimensional analyses of drugs used to treat skin diseases or to examine the microstructure of elastin networks
    corecore