Relationship between HBsAg detected in liver tissue and liver injury.
Explore the source record for details and available documents.
Carrier State↗
Biomedical subjects
G Dong
Publications and source records attributed to G Dong.
Altered Gene Expression during Auxin-Induced Root Development from Excised Mung Bean Seedlings.
Changes in the pattern of protein synthesis and in the translatable mRNA population have been examined during auxin-induced root development from excised mung bean seedlings. Several proteins, predominantly of low molecular weight and high pI, as shown by two-dimensional polyacrylamide gel electrophoresis, are synthesized specifically by auxin-treated tissue. These auxin-induced proteins appear between 6 and 12 hours of auxin treatment, reach a maximum at 24 hours, and decline at 48 hours. Untreated seedlings (placed in Hoagland solution), known to produce small number of roots at the cut end probably due to endogeneous auxin accumulated at the cut end through basipetal transport, show low level synthesis of auxin-specific proteins. Antiauxin treatment that completely inhibits auxin-induced rooting also prevents the appearance of auxin-induced proteins. The induction of a group of three to four proteins appears to be specific to antiauxin treatment. In vitro translation of mRNA from auxin-treated tissue, but not of mRNA from antiauxin-treated tissue, yields several polypeptides of low molecular weight and high pI. Since the auxin-induced proteins precede root development and are synthesized transitorily, it is likely that they play some regulatory role during the initiation of root development. The result show that auxin-induced root formation involves altered gene expression.
Journal Article↗
Aged skin: a study by light, transmission electron, and scanning electron microscopy.
The fine structural organization of the epidermis, dermal/epidermal junction, and dermis from an unexposed site (upper inner arm) of elderly people was compared with the organization of a similar region of young people. Despite an overall thinning of the epidermis and focal areas of cytologic atypia, the characteristic morphological markers associated with the keratinization process are not markedly altered in appearance or amount. A well-formed stratum corneum consisting of flattened, enucleated horny cells enveloped by a thickened membrane, and intracellular spaces filled with electron-dense material provide structural evidence that barrier ability is not compromised in senile skin. The dermal/epidermal changes in aged skin are marked and have significant physiologic implications. The major change is a relatively flat dermal/epidermal junction resulting from the retraction of the epidermal papillae as well as the microprojections of basal cells into the dermis. This flattening results in a more fragile epidermal/dermal interface and, consequently, the epidermis is less resistant to shearing forces. Retraction of the epidermal downgrowths (preferential sites of the putative epidermal stem cell) may also explain the loss in proliferative capacity associated with the aged epidermis. The three-dimensional arrangements of collagen and elastic fibers showed marked alterations with age. Both fibrous components appear more compact because of a decrease in spaces between the fibers. Collagen bundles appear to unravel, and the individual elastic fibers show signs of elastosis. These changes may contribute to the loss of resilience that is one of the salient features of senile skin.
Adult↗
Identification of a chymotrypsin-like proteinase in human mast cells.
An antiserum was produced against a chymotryptic proteinase purified from human skin. The antiserum did not cross-react with human leukocyte cathepsin G and elastase, rat mast cell proteinase I, and human skin tryptase. Indirect immunofluorescent staining of frozen skin sections to localize the proteinase showed cytoplasmic staining of cells scattered about the papillary dermis and around blood vessels and appendages. Restaining these sections with toluidine blue revealed that the fluorescently stained cells contained metachromatically staining granules, the major distinguishing feature of mast cells. A similar correlation was found in lung tissue. Ultrastructural studies employing the ferritin bridge technique to immunologically identify the proteinase additionally localized the proteinase to mast cell granules. Biochemical and immunochemical characterization of chymotryptic activity solubilized from isolated human lung mast cells identified a chymotryptic proteinase that may be identical to the skin chymotryptic proteinase. These studies establish that human skin mast cells contain a chymotrypsin-like proteinase that is a granule constituent and provide evidence that indicates a comparable proteinase is also present in lung mast cells.
Chymases↗
Morphology of aged skin.
Despite an overall thinning of the epidermis and focal areas of cytologic atypia, there was no morphologic evidence that the protective function of this tissue was compromised by age. The characteristic morphologic markers associated with the keratinization process were not altered either in appearance or in amounts. A well-formed stratum corneum was present, suggestive that barrier ability is not compromised in senile skin. Whereas alterations in the aged epidermis are slight, the dermal-epidermal changes are marked and have greater physiologic consequences. The major change is a relatively flat dermal-epidermal junction because of retraction of the epidermal papillae as well as the microprojections of basal cells into the dermis. This flattening results in a more fragile tissue less resistant to shearing forces. Retraction of the epidermal downgrowths may also explain the loss in proliferative capacity associated with the aged epidermis. The major alterations in the aged dermis concern the architecture of the collagen and elastin networks. Both fibrous components appear more compact because of a decrease in the voids or spaces between the fibers; the spaces resulted from a loss of ground substance. Collagen bundles appear to unravel, and the individual elastic fibers show signs of elastolysis. The net effect of these fibrous rearrangements and alterations is a dermis that is less stretchable, less resilient, more lax, and prone to wrinkling.
Aged↗