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Biomedical subjects

J R Wagner

Publications and source records attributed to J R Wagner.

At least 73 records · Page 4Linked to original sources
PubMed1989

Long-term phorbol ester treatment dissociates phospholipase D activation from phosphoinositide hydrolysis and prostacyclin synthesis in endothelial cells stimulated with bradykinin.

Bovine pulmonary artery endothelial cells (BPAEC) were prelabeled with [3H]choline or [3H]myristic acid to selectively label endogenous phosphatidylcholine. BPAEC were stimulated with ATP and bradykinin (BK), and phospholipase D (PLD) activation was detected as a 4-fold increase in [3H]choline in cells prelabeled with [3H]choline or as a 2- to 3-fold increase in [3H]phosphatidylethanol in cells prelabeled with [3H]myristic acid and stimulated in the presence of ethanol. Pretreatment of BPAEC with 0.1 microM phorbol 12-myristate 13-acetate (PMA) for 22 hr completely inhibited agonist-induced PLD activation, whereas prostacyclin synthesis and [3H]phosphoinositide ([3H]PIns) hydrolysis were enhanced in pretreated cells. Long-term PMA treatment thus dissociates agonist-induced PLD activation from [3H]PIns hydrolysis, and agonist-induced prostacyclin synthesis is not dependent upon PLD activation.

6-Ketoprostaglandin F1 alpha↗
PubMed1989

Clinical and histological case study using resorbable hydroxylapatite for the repair of osseous defects prior to endosseous implant surgery.

A clinical case--a follow-up clinical and histological study--is presented in this paper, which describes the use of resorbable hydroxylapatite [OsteoGen (H.A. Resorb), Impladent, Inc., & GBD Marketing Group, Inc., Medical Division, Valley Stream, NY 11580] for the repair of a large mandibular lesion, followed by the placement of an endosseous dental implant six weeks after the graft placement. A comparison of the histological results of four-month and 14-month bone biopsies of resorbable hydroxylapatite grafts is included in this report.

Adult↗
PubMed1989

Aortic graft-enteric fistula and paraprosthetic-enteric fistula: a review.

AGEF/PPEFs are infrequent, life-threatening complications of aortic reconstructive surgery. Early diagnosis requires a high index of suspicion. Whenever a patient with an aortic prosthesis develops gastrointestinal bleeding or manifestations of sepsis, the presence of a fistulous complex should be assumed until proven otherwise. In the vast majority of cases, adequate surgical management requires graft excision with extraanatomic bypass. Widespread retroperitoneal infection precludes any attempt at local revascularization.

Aorta, Abdominal↗
PubMed1987

Specific deprotonation reactions of the pyrimidine radical cation resulting from the menadione mediated photosensitization of 2'-deoxycytidine.

Menadione(2-methyl-1,4-naphthoquinone) was shown to sensitize 2'-deoxycytidine to near ultraviolet light according to two main mechanisms. Reaction of a water molecule with the initially photo-induced pyrimidine radical cation and subsequent addition of molecular oxygen leads to the preponderant formation of the four cis and trans diastereoisomers of 5,6-dihydroxy-5,6-dihydro-2'-deoxyuridine. Pyrimidine ring opening and rearrangement products are also generated through the intermediate 6-hydroxy-5,6-dihydro-2'-deoxyurid-5-yl radical. The competitive deprotonation reaction of the radical cation is likely to involve two sites. Loss of an amino group proton is the likely initial event to explain the formation of 2'-deoxyuridine which is resistant to further photooxidation. The second deprotonation reaction involves the osidic carbon C(1'). The resulting radical will further react with oxygen leading to the release of free cytosine with concomitant formation of 2-deoxy-D-ribono-1,4-lactone. This reaction which is not prevented by hydroxyl radical scavengers constitutes to our knowledge the first example of a pyrimidine radical which is able to initiate selective intramolecular reaction at position 1 within the sugar moiety.

Carbon Radioisotopes↗
PubMed1986

Photosensitized reactions of nucleic acids.

The main effects of near-ultraviolet and visible light on cellular DNA are reviewed with emphasis on base lesions, oligonucleotide single-strand breaks and DNA-protein cross-links. Model system photosensitization reactions of DNA are also discussed. This includes photodynamic effects, menadione-mediated photooxidation, photoionization of antibiotics, the photochemistry of 5-halogenopyrimidines and urocanic acid.

4-Aminobenzoic Acid↗
PubMed1986

Sensitized photo-oxidation of thymidine by 2-methyl-1,4-naphthoquinone. Characterization of the stable photoproducts.

The near ultraviolet photolysis of an aerated aqueous solution of thymidine containing 2-methyl-1,4-naphthoquinone gives rise to two main classes of photoproducts as a result of the initial formation of a pyrimidine radical cation. These photo-oxidation products have been separated by high performance liquid chromatography and further characterized by various spectroscopic techniques including fast atom bombardment mass spectrometry and high field 1H and 13C nuclear magnetic resonance analysis. This photoreaction constitutes an excellent model to study the chemical properties of the thymidine radical cation which is expected to be one of the primary consequences of the direct effects of ionizing radiation.

Oxidation-Reduction↗
PubMed1979

Development of a multifunctional drug file for hospital pharmacy computer applications.

The development of a multifunctional master drug file (MDF) which satisfies initial pharmacy data base requirements and has the capability to support increasingly sophisticated computer applications is described. The computerized purchasing, inventory, drug use review and formulary systems in a 1,100-bed teaching hospital were evaluated to determine which existing data fields should be included in the MDF, Functional requirements for the MDF and 27 data fields, each with its own particular specifications for programming, were identified. A method of data input was designed to create and maintain the file using keypunched Hollerith cards. Data input forms were designed to serve as coding documents for drug file data. Verification of all data in the file can be performed by running a program which lists the contents of each drug recorded. Based on 1975 salary rates, the total cost of the MDF development was $4,010; total time required was 640 hours. Approximately one hour per week is needed to keep the file contents up to date. File design specifications and contents are discussed, with special emphasis on the functional aspects of the MDF. The MDF successfully fulfilled the initaial pharmacy computer system requirements and has the potential to accommodate increasingly sophisticated applications.

Computers↗
PubMed1978

Distributed processing techniques: interface design for interactive information sharing.

The Information Systems Division of the University of Iowa Hospitals and Clinics has successfully designed and implemented a set of generalized interface data-handling routines that control message traffic between a satellite minicomputer in a clinical laboratory and a large main-frame computer. A special queue status inquiry transaction has also been developed that displays the current message-processing backlog and other system performance information. The design and operation of these programs are discussed in detail, with special emphasis on the message-queuing and verification techniques required in a distributed processing environment.

Computers↗