Biomedical subjects

D W Easter

Publications and source records attributed to D W Easter.

22 records · Page 2Linked to original sources

PubMed1990

Laparoscopic repair/peritoneal toilet of perforated duodenal ulcer.

Laparoscopic techniques have been refined to the point where exposure, haemostasis and tissue approximation by suture approach those obtained at open access surgery. We report a patient with acute perforation of an ulcer in the first part of the duodenum who was successfully treated by laparoscopic oversewing and omental patching. The clinical indications for contemplating use of laparoscopic surgery for acute ulcer perforation, techniques employed and the areas for potential improvement of instruments, needles and sutures are discussed.

Adult↗

PubMed1989

Recent trends in the management of desmoid tumors. Summary of 19 cases and review of the literature.

Recent advances in the understanding of desmoid tumor biology affect therapeutic choices. This series of 19 patients and review of the literature outlines historic perspectives and discusses the options in the management of these locally aggressive tumors. Desmoid tumors tend to grow steadily, regardless of tumor location. However differences in the aggressive nature of these tumors are seen when age and sex distributions are scrutinized. Although recurrence rates are high, excisional therapy is the best first approach. An exception is the case in which tumor excision is either particularly dangerous or likely to result in significant physical handicap. Radiation or drug therapy are most often used with recurrent disease or as an alternative to mutilating surgery. Although many pharmacologic approaches have been advocated, (including antiestrogen therapy, cyclic-AMP, and prostaglandin inhibition), results are anecdotal at best.

Abdominal Muscles↗

PubMed1988

Immunosuppression by a peptide from the gelatin binding domain of human fibronectin.

Circulating immunosuppressive peptides are found in conjunction with elevated protease activity in injured patients' serum. Previous work suggests that fibronectin may be a source of these peptides. Elastase-generated fibronectin degradation products were chromatographically separated and assessed for immunosuppressive capacity in the neutrophil chemotaxis and mixed lymphocyte reaction bioassays. The suppressive fibronectin degradation products fraction 22 inhibited chemotaxis by 53% (P less than 0.01) and mixed lymphocyte reaction by 41% (P less than 0.001). Incubation of the suppressive fraction 22 with gelatin, neuraminidase, or anti-SAP (suppressor active peptide) antibody reverses the chemotaxis inhibition to control values. These results indicate that an elastase-generated fragment of fibronectin, which potently inhibits neutrophil and lymphocyte activity, is located within the sialated gelatin binding portion of the molecule. Immunosuppression reversal by anti-SAP antibody, and the requirement for sialic acid, suggests similarity between fraction 22 and SAP, although other explanations are plausible. This peptide fragment from fibronectin may impact on the clinical immunosuppression seen in patients following severe trauma.

Fibronectins↗

PubMed1983

Structural integrity of hepatocyte tight junctions.

The significance of discontinuities frequently found in freeze-fracture replicas of the tight junction was evaluated using complementary replicas of hepatocyte junctions from control and bile duct-ligated rats. An extensive analysis of complementary replicas using rotary platinum shadowing indicates that discontinuities in the protoplasmic (P) fracture face do not represent structural breaks in the tight-junctional network. In no case did P-face discontinuities correspond with interruptions in the groove network on the complementary extracellular (E) face. Quantitative analysis of replicas shows that P-face discontinuities result in part from "transfer" of material to the complementary E face (approximately 7% of the junctional length). However, many P-face discontinuities (7-30% of the junctional length) are matched only by a groove on the complementary E face. This finding demonstrates that a significant amount of material can be lost during freeze-fracture. An analysis of junctions from bile duct-ligated rats, which are known to have an increased paracellular permeability, shows comparable transfer and loss of material. However, the number of junctional elements and the tight-junction network density was significantly reduced by bile duct ligation. These observations indicate that discontinuities in tight-junctional elements result during the preparation of freeze-fracture replicas and are not physiologically important features of the junctional barrier. Variation in the number of elements provides the best explanation for observed differences in tight-junction permeability.

Animals↗