Johns Hopkins University School of Medicine

About: Johns Hopkins University School of Medicine is a healthcare organization based out in Baltimore, Maryland, United States. It is known for research contribution in the topics: Population & Medicine. The organization has 44277 authors who have published 79222 publications receiving 4788882 citations.

“Components Separation” Method for Closure of Abdominal-Wall Defects: An Anatomic and Clinical Study

Abstract: Closure of large abdominal-wall defects usually requires the transposition of remote myocutaneous flaps or free-tissue transfers. The purpose of this study was to determine if separation of the muscle components of the abdominal wall would allow mobilization of each unit over a greater distance than possible by mobilization of the entire abdominal wall as a block. The abdominal walls of 10 fresh cadavers were dissected. This demonstrated that the external oblique muscle can be separated from the internal oblique in a relatively avascular plane. The rectus muscle with its overlying rectus fascia can be elevated from the posterior rectus sheath. The compound flap of the rectus muscle, with its attached internal oblique-transversus abdominis muscle, can be advanced 10 cm around the waistline. The external oblique has limited advancement. These findings were utilized clinically in the reconstruction of abdominal-wall defects in 11 patients, ranging in size from 4 x 4 to 18 x 35 cm. This study suggests that large abdominal-wall defects can be reconstructed with functional transfer of abdominal-wall components without the need for resorting to distant transposition of free-muscle flaps.

Broccoli sprouts: An exceptionally rich source of inducers of enzymes that protect against chemical carcinogens

Abstract: Induction of phase 2 detoxication enzymes [e.g., glutathione transferases, epoxide hydrolase, NAD(P)H: quinone reductase, and glucuronosyltransferases] is a powerful strategy for achieving protection against carcinogenesis, mutagenesis, and other forms of toxicity of electrophiles and reactive forms of oxygen. Since consumption of large quantities of fruit and vegetables is associated with a striking reduction in the risk of developing a variety of malignancies, it is of interest that a number of edible plants contain substantial quantities of compounds that regulate mammalian enzymes of xenobiotic metabolism. Thus, edible plants belonging to the family Cruciferae and genus Brassica (e.g., broccoli and cauliflower) contain substantial quantities of isothiocyanates (mostly in the form of their glucosinolate precursors) some of which (e.g., sulforaphane or 4-methylsulfinylbutyl isothiocyanate) are very potent inducers of phase 2 enzymes. Unexpectedly, 3-day-old sprouts of cultivars of certain crucifers including broccoli and cauliflower contain 10-100 times higher levels of glucoraphanin (the glucosinolate of sulforaphane) than do the corresponding mature plants. Glucosinolates and isothiocyanates can be efficiently extracted from plants, without hydrolysis of glucosinolates by myrosinase, by homogenization in a mixture of equal volumes of dimethyl sulfoxide, dimethylformamide, and acetonitrile at -50 degrees C. Extracts of 3-day-old broccoli sprouts (containing either glucoraphanin or sulforaphane as the principal enzyme inducer) were highly effective in reducing the incidence, multiplicity, and rate of development of mammary tumors in dimethylbenz(a)anthracene-treated rats. Notably, sprouts of many broccoli cultivars contain negligible quantities of indole glucosinolates, which predominate in the mature vegetable and may give rise to degradation products (e.g., indole-3-carbinol) that can enhance tumorigenesis. Hence, small quantities of crucifer sprouts may protect against the risk of cancer as effectively as much larger quantities of mature vegetables of the same variety.

Tissue repair and stem cell renewal in carcinogenesis

Abstract: Cancer is increasingly being viewed as a stem cell disease, both in its propagation by a minority of cells with stem-cell-like properties and in its possible derivation from normal tissue stem cells. But stem cell activity is tightly controlled, raising the question of how normal regulation might be subverted in carcinogenesis. The long-known association between cancer and chronic tissue injury, and the more recently appreciated roles of Hedgehog and Wnt signalling pathways in tissue regeneration, stem cell renewal and cancer growth together suggest that carcinogenesis proceeds by misappropriating homeostatic mechanisms that govern tissue repair and stem cell self-renewal.