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Biomedical subjects

E Rich

Publications and source records attributed to E Rich.

29 records · Page 2Linked to original sources
PubMed1990

[Clinical comparison of different cervical fillings after one year].

Cervical lesions in 38 patients were restored using composite resins (n = 57), the "sandwich-technique" (n = 64) or glassionomercement (n = 66). Immediately following insertion and 4, 8, and 12 months later, the restorations were examined clinically and in the SEM. Two composite fillings and one filling each of the two other types of restoration were lost. After one year the quality of the dentinal margins of the composite restorations was statistically (p less than 0.05) inferior to the two other methods. Margin quality in enamel was rated superior (p less than 0.05) with glassionomercement as against the other materials. Clinically, the composite filling yielded poorer results regarding marginal integrity and discoloration, although in general they showed superior esthetics. In restoring cervical lesions the use of glassionomercements or the "sandwich-technique" has definite advantages over composite fillings. For the evaluation of new restorative materials and techniques, SEM should be used in addition to clinical examinations.

Adolescent↗
PubMed1989

Transglutaminase-mediated cross-linking of fibrinogen by human umbilical vein endothelial cells.

The interaction of endothelial cells with soluble or substrate-immobilized 125I-labeled fibrinogen (125I-FGN) was analyzed. Binding experiments involved incubation of 125I-FGN with cell suspensions at 4 degrees C. Bound ligand was quantitated by centrifugation of cells through silicone oil followed by scintillation analysis of the cell pellet. Calcium-dependent binding of 125I-FGN reached a maximum after 3 h and represented about 60% of the total. Half-maximal saturation occurred at 60 nM, and about 9 x 10(4) molecules were bound/cell at saturation (approximately 100 nM). Calcium-dependent binding was completely inhibited by unlabeled fibrinogen, partially inhibited by a monoclonal antibody (7E3) against glycoprotein IIb-IIIa, but not inhibited by fibrinogen fragments D or E, an anti-glycoprotein IIIa polyclonal antibody, or the Arg-Gly-Asp-Ser tetrapeptide. In contrast, the Arg-Gly-Asp-Ser tetrapeptide as well as the monoclonal antibody 7E3 markedly inhibited attachment of endothelial cells to substrate-immobilized fibrinogen, whereas fragment D or E did not. Both in suspension and monolayer, the 125I-FGN underwent cross-linking involving principally the A alpha chain. The transglutaminase inhibitors putrescine, histamine, and cystamine interfered with 125I-FGN binding and cross-linking by suspended cells. Since cross-linking in suspension was limited to bound 125I-FGN and since transglutaminase activity was not detectable in the binding buffer, cross-linking may have been mediated by a cell-associated transglutaminase.

Amino Acid Sequence↗
PubMed1989

Algorithms for evaluating the appropriateness of blood transfusion.

Medicare regulations and the guidelines of the Joint Commission on Accreditation of Healthcare Organizations require assessment of the appropriateness of transfusions by a hospital committee. A set of criteria maps for component transfusion review by nurses or technical personnel was designed, tested, and modified. The algorithms were based on written guidelines developed by a group of physicians. In the first part of the study, 196 medical records of patients from medical and surgical diagnosis-related groups with the highest utilization of blood (Group I) were screened. Forty patients were excluded because of a preexisting transfusion protocol. Of the remaining 156 patients, 146 (94%) received red cell transfusions, of which 96 percent were indicated, 1 percent not indicated, and 3 percent controversial. Thirty-five patients (22%) received fresh-frozen plasma transfusions, of which 69 percent were indicated, 11 percent not indicated, 17 percent controversial, and 6 percent indeterminate. In the second part of the study, medical records were screened from 99 randomly selected patients who had received red cell transfusions (Group II), and the results were similar to those in Group I. Physician review was necessary in 20 percent of the transfused patients screened with the criteria maps. It is concluded that algorithms for transfusion review can be developed and used easily to fulfill regulatory and accreditation requirements and to plan focused educational programs.

Adolescent↗
PubMed1988

Binding and cross-linking of rabbit fibronectin by rabbit hepatocytes in suspension.

Fibronectin purified from rabbit plasma was radioiodinated, and its interaction with rabbit hepatocytes in suspension was studied. Iodinated fibronectin interacted in a time-dependent fashion reaching plateau at 3 h. The interaction was greater in the presence of calcium than in the presence of magnesium or EDTA. Saturation occurred at about 140 nM fibronectin with about 1,400,000 molecules bound per cell. The interaction could be inhibited by unlabeled fibronectin or fibrinogen but not by the tetrapeptide Arg-Gly-Asp-Ser or by albumin, transferrin, or fetuin. About 50% of the bound iodinated fibronectin was incorporated, in a calcium-dependent fashion, into cross-linked high molecular weight complexes at the cell surface through a mechanism consistent with a cellular transglutaminase-mediated reaction. Iodinated fibronectin which could be displaced from the cell was monomeric in nature, while the cell-associated material remained in high molecular weight complexes. The role of the interaction is currently under investigation, but it is possible that the binding may promote cellular adhesion or facilitate intercellular interaction.

Animals↗
PubMed1967

Prevention of protein denaturation during exposure to sterilization temperatures.

Firefly luciferase exposed to a temperature of 135 degrees C for 36 hours re tained up to 40 percent of its original activity. Prerequisites for heat stability were the use of a molecular sieve (Seph adex G-25 or Biogel P-300) and a high vacuum (5 x 10(-4) mm-Hg). These studies present a possible solution to the problem of sterilization for exobiologi cal experiments.

Adenosine Triphosphate↗