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Biomedical subjects

D Lund

Publications and source records attributed to D Lund.

6 recordsLinked to original sources
PubMed1991

The spectrum of liver and spleen injuries in children: failure of the pediatric trauma score and clinical signs to predict isolated injuries.

STUDY OBJECTIVES: To determine whether potentially life-threatening intra-abdominal injuries occur in the absence of multisystem trauma in children, and to determine the usefulness of physical examination and a pediatric triage score in the assessment of liver and spleen injuries in children. DESIGN: Retrospective study. SETTING: Admissions to a children's hospital from October 1982 through September 1989 who were found to have liver or spleen injuries. Seventy-seven patients were identified; 55 were male, 22 were female. Mean age was 9 years and 3 months (+/- 56 months) with a range of 22 months to 20 years, 4 months. Clinical signs were recorded and a Pediatric Trauma Score (PTS) and Injury Severity Score (ISS) were calculated for each patient. MEASUREMENTS AND MAIN RESULTS: Fifty-four patients (70%) had a spleen injury, 18 (23%) had a liver injury, and five (7%) had both liver and spleen injuries. Patients were managed without surgery in 63 of 77 cases (82%); two died. Fifty-one of 77 patients (66%) received an ISS of 18 or less; 26 patients (34%) received a score of more than 18. Forty-four of the 51 patients (86%) with an ISS of 18 or less had a normal pulse (120 or less); 48 of the 51 (94%) had a normal systolic blood pressure (90 mm Hg or more). A strong negative correlation (r = -0.80; P = .001) was found between the two scores for children with multiple severe injuries (ISS of more than 18); there was poor correlation (r = -0.04; P greater than .05) between the two scores for isolated liver or spleen injury (ISS of 18 or less). CONCLUSIONS: We conclude that liver or spleen damage may be present in children without other injuries and must be considered with a high index of suspicion, and that neither the initial clinical findings nor the PTS reliably predicts liver or spleen injuries in children with focal abdominal injuries.

Adolescent↗
PubMed1987

Target tissue distribution of the proenkephalin peptides F, E, and B.

The adrenal medulla is a rich source of endogenous opioid peptides. These peptides exist predominantly in the form of larger (25-34 amino acid long) enkephalin containing peptides, whose biological roles have yet to be elucidated. We report here the tissue binding distribution of three iodinated enkephalin containing peptides, Peptides F, E, and B, in rats, rabbits, and guinea pigs following intravenous injection. Each [125I]peptide has a unique distribution profile but all three are found to bind to the pituitary in each species of animal examined. A number of lines of evidence point toward the enkephalin containing peptides, Peptides F, E, and B, having physiological roles distinct from the enkephalins. The distribution profile of these [125I]peptides reported here gives insight into their potential effector sites.

Animals↗
PubMed1987

Extracorporeal enzymatic heparin removal: use in a sheep dialysis model.

Extracorporeal medical devices such as the hemodialyzer rely on systemic heparinization to prevent thrombus formation. Heparin, however, can lead to serious hemorrhagic complications. A blood filter containing immobilized heparinase, a heparin specific enzyme, was used to degrade heparin into small fragments which have significantly less anticoagulant activity than the parent compound. The heparinase filter was tested in the extracorporeal circuit during the hemodialysis of adult sheep. At a blood flow of 200 ml/min, the clearance of heparin varied from 50 to 70 ml/min (N = 16) depending on the amount of immobilized heparinase in the filter. Hemolysis was insignificant as measured by the animals' red cell counts, hematocrit, total hemoglobin and a plasma-free hemoglobin value of 89 +/- 33 mg/dl (N = 16) (less than 1% of the total hemoglobin). The white cell counts dropped to 47 +/- 7% (N = 16) of the initial value at 20 minutes and rebounded to 72 +/- 10% (N = 16) after one hour. The platelet counts decreased to 55 +/- 8% (N = 16) of the initial value after one hour. No change in heparin clearance was observed when reactors were used repeatedly in adult sheep over a 10 week period. The red cell counts, white cell counts, platelet counts, total hemoglobin and hematocrit did not change after 10 weeks of exposure to the device. These results suggest that with further study, heparinase may be useful in removing heparin used to anticoagulate blood in extracorporeal circuits.

Animals↗
PubMed1985

Angiogenesis is stimulated by a tumor-derived endothelial cell growth factor.

A growth factor mitogenic for BALB/C 3T3 cells and capillary endothelial cells was isolated from a rat chondrosarcoma and purified to homogeneity. Purification was accomplished by a combination of BioRex 70 cation exchange chromatography and heparin affinity chromatography. The pure chondrosarcoma-derived growth factor (ChDGF) had a molecular weight of about 18,000. The angiogenesis activity of pure ChDGF was tested by measuring its ability to vascularize the chorioallantoic membrane (CAM) and yolk sac membrane of the developing chick. The ability of ChDGF to induce the growth of limbal vessels in the rat cornea was also measured. To quantitate the angiogenesis response, a unit system based on the growth factor activity of ChDGF for 3T3 cells was adopted. ChDGF was found to have a specific activity of about 5 units/ng when applied to 3T3 cells. About 300-600 units of ChDGF in the two types of developing chick membrane and 30-5 units of ChDGF in the rat cornea were found to stimulate noninflammatory angiogenesis.

Animals↗