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  • 1
    ISSN: 1365-2133
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background  Alopecia areata (AA) is hypothesized to be an organ-specific autoimmune disease with genetic predisposition and an environmental trigger. There are few clinical data in Asians.Objectives  To describe the genetic epidemiological features of AA patients in China and to determine the possible genetic model for AA.Methods  Data for 1032 patients with AA were obtained by questionnaire in the Institute of Dermatology of Anhui Medical University in China from 2001 to 2003. Complex segregation analysis and heritability analysis were performed using Falconer's method, EPI INFO 6·0 and SAGE-REGTL programs.Results  In total, 1032 AA patients (male/female ratio 1·1 : 1) were enrolled, representing 0·94% of the total number of cases seen in our outpatient clinic during that time. The mean ± SD age of onset was 28·98 ± 13·43 years. The difference between the mean age of onset in males and females was not significant. Most patients (82·6%) experienced their first episode of AA within the first four decades of life. A positive family history of AA was obtained in 87 patients (8·4%). The prevalence of AA in first-, second- and third-degree relatives of the proband with AA was 1·6%, 0·19% and 0·03%, respectively. These figures were higher than those in controls. A greater severity and longer duration of AA were seen in the early onset group than in the late-onset group. The early onset group also had more affected first- and second-degree relatives. The heritability of AA in first-, second- and third-degree relatives was 47·16%, 42·53% and 22·29%, respectively. Based on the REGTL results, the best model was a polygenic additive model for AA.Conclusions  The effect of genetic factors is strong in AA, but environmental factors such as infection and psychological stress may still play an important role. Our findings on the genetics of AA are consistent with a polygenic additive mode of inheritance.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1600-0765
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: After severe injury to the periodontal ligament (PL), the phenotypes of cells recolonizing root surfaces influence the extent and type of repair processes. In teeth that are replanted following avulsion injury, recolonization of the PL space by osteogenic cells instead of by PL fibroblasts may favor bone formation (i.e. ankylosis) instead of PL regeneration. We consider here that recolonization processes depend in part on the storage conditions of the teeth following avulsion. We used an in vitro cell culture model to assess the effect of storage conditions on immunohistochemical staining of several marker proteins that are expressed by osteogenic cells (osteopontin and alkaline phosphatase) and fibroblasts (α-smooth muscle actin, type III and XII collagens). Prior to cell culture, extracted human premolar teeth were stored in air (“dry”) or in α-MEM (“wet”) for either 30 or 120 min as surrogate conditions for the variations of extra-alveolar tooth storage that may occur following avulsion. Collagenase/trypsin-digested suspensions of PL cells were prepared from the tissue adherent to the extracted root surface. Passage #2 or #3 cultures were immunostained and examined by fluorescence microscopy. For type XII collagen, cells from wet samples displayed perinuclear staining while cells from 30-min dry samples showed only isolated foci. The staining for 120-min dry samples was weak and non-specific. α-Smooth muscle actin was not incorporated into stress fibers in wet samples, whereas dry samples demonstrated prominent stress fibers stained for α-smooth muscle actin. Detached cytoplasmic fragments resembling cell processes that stained for α-smooth muscle actin were abundant in dry samples, indicating the presence of highly contractile cells. The staining for osteopontin was mainly perinuclear but was more intense in dry samples. The focal adhesion pattern of osteopontin staining in 120-min dry samples resembled that of migrating osteogenic cells. The pattern of staining did not vary for type III collagen or alkaline phosphatase, although staining for alkaline phosphatase was more intense in samples stored under dry conditions. We conclude that prolonged extra-alveolar dry storage favors increased in vitro growth of contractile cells expressing osteogenic cell markers while storage in cell culture medium favors growth of cells with the classical phenotype of PL fibroblasts.
    Type of Medium: Electronic Resource
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