PubMed HealthSearch

Biomedical subjects

V Dunn

Publications and source records attributed to V Dunn.

5 recordsLinked to original sources

Detection of heterotopic gray matter in children by magnetic resonance imaging.

Heterotopic gray matter results from abnormal brain development and is a recognized focus of seizures. It may be associated with mental retardation and/or severe malformations of the brain. Three patients with heterotopia of gray matter were identified by magnetic resonance imaging (MRI). CT failed to detect the heterotopic gray matter in each case. One child was referred for removal of a neoplasm based on CT studies until MRI demonstrated the developmental nature of his condition. One infant had severely dysplastic left cerebral hemisphere associated with heterotopic gray matter and the syndrome of Hypomelanosis of Ito. All three children suffered from seizures and/or mental retardation. MRI provided important information in the management of each case and appears to be the imaging method of choice in evaluating children with seizures or retardation for heterotopic gray matter in the brain.

Brain Neoplasms

Jejunal diverticulosis and chronic pneumoperitoneum.

A unique case of pneumoperitoneum, without peritonitis or perforation, associated with jejunal diverticulosis is presented. Pneumoperitoneum is documented over the course of many years, with recurrence after partial small bowel resection. Jejunal diverticulosis is one of the leading gastrointestinal causes of pneumoperitoneum without peritonitis or surgery. The distended diverticular mucosa may function as a semipermeable membrane allowing transmural gas equilibration.

Aged

Hemodynamic studies using a CT scanner.

New CT software programs allow rapid-sequence images to be obtained. During a period of 12 sec, multiple CT images can be produced, so that the progression of contrast flow at intervals of 1 sec or less can be followed. In addition, as many as 16 consecutive 3-sec scans can be performed, or arbitrary time intervals inserted between scans. The rapidity with which the contrast medium enters and leaves a specific tissue may be a valuable, non-invasive diagnostic tool in differentiating enhancing lesions. Other potential applications are mentioned.

Hemodynamics

Familial hyperphosphatasemia: diagnosis in early infancy and response to human thyrocalcitonin therapy.

Familial hyperphosphatasemia is an uncommon hereditary disorder of membranous bone with concurrent overproduction and overdestruction of bone and bone collagen by osteocytes. This process does not allow normal maturation into compact lamellar bone. Two cases of severely affected children are presented which demonstrate that the condition can be diagnosed in early infancy by abnormalities in the long bones. At this stage the skull may appear normal and the characteristic thickening of the calvarium appears later. The disease is treatable with human thyrocalcitonin; these and previously reported cases have responded favorably.

Age Factors

Ferritin and intestinal iron absorption: pancreatic enzymes and free iron.

Rat intestinal mucosa gave low yields of ferritin purified by standard procedures. The resulting ferritin had less protein relative to iron and migrated faster electrophoretically than ferritin from other rat tissues. Pancreatic duct ligation reduced these differences, suggesting digestive enzyme attack during ferritin isolation. Even in ligated rats, ferritin accounted for only 5-10% of mucosal iron. However, shortly after giving 59FeCl3 orally, 50% of mucosal radioactivity occurred in cell sap, about equally distributed between ferritin and low-molecular-weight (chelated?) iron. No other cell sap components were 59Fe labeled. Iron may thus be transported as a chelate with which ferritin is in rapid equilibrium. Mucosal ferritin content increased with age and iron treatment and decreased with iron deficiency. The iron-deficient rats showed accelerated 59Fe uptake into blood with little mucosal retention. One day after administering parenteral iron to deficient rats, 59Fe transfer to blood became retarded but 59Fe now accumulated excessively in the mucosa, suggesting that iron status affects transport more rapidly at the serosal than at the mucosal cell surface. A scheme for control of iron absorption is presented.

Age Factors