Biomedical subjects
Publications and source records attributed to R Bruce.
Six of 175 Angus heifers died after ingesting excessive amounts of Durango root (Datisca glomerata). Animals had rumens full of Durango root, were extremely lethargic, and had diarrhea prior to death. The animals had nonspecific postmortem lesions. This case is discussed in light of previous findings from trials in which Durango root was experimentally fed to cattle.
Primary and early subcultures (1st- to 3rd passage) of human umbilical vein endothelial cells produce tissue-type plasminogen activator (t-PA) antigen, consisting only of a major Mr 110,000 t-PA form. Later subcultures (greater than 4th passage) produce increasing amounts of t-PA antigen, consisting of a major Mr 110,000 and a minor Mr 68,000 form as well as increasing amounts of urokinase-type plasminogen activator (u-PA) antigen, consisting of a minor Mr 95,000 and major Mr 54,000 form. All of the major plasminogen activator forms were purified to homogeneity from 72 h serum-free conditioned media (3 liters, 1-1.8 x 10(9) cells) by a combination of immunoaffinity and gel filtration chromatography. Typically, 4th to 6th passage cultures produced/secreted t-PA-type proteins consisting of an inactive Mr 110,000 (220 IU/mg) and active Mr 68,000 (76,500 IU/mg) form representing about 39 and 8%, respectively, of the total starting sodium dodecyl sulfate stable t-PA activity, and u-PA-type proteins consisting of an inactive Mr 95,000 (700 IU/mg) and active Mr 54,000 (81,000 IU/mg) form representing about 9 and 38%, respectively, of the total starting sodium dodecyl sulfate stable u-PA activity. The isolated Mr 68,000 t-PA and Mr 54,000 u-PA proteins, exist only as two-chain forms in the absence of aprotinin and as mixtures of single- and two-chain proteins in the presence of aprotinin. Treatment with nucleophilic agents completely dissociated the Mr 110,000 t-PA and Mr 95,000 u-PA proteins into their respective Mr 68,000 t-PA and Mr 54,000 u-PA activity forms and a common Mr 46,000 protein, confirming the enzyme-inhibitor complex nature of these inactive plasminogen activator forms.
Single-chain Mr 54,000 u-PA (scu-PA) was isolated, in the presence of aprotinin, from 3-liter batches of 60-h serum-free conditioned media obtained from subcultured (4-6th passage) human umbilical vein endothelial cells (HUVECs, approximately 1.8 x 10(9) cells). In the presence of heparin and endothelial cell growth factor, subcultured human umbilical vein endothelial cells produced u-PA proteins consisting of about 85-90% Mr 54,000 scu-PA and 10-15% two-chain Mr 54,000. The major scu-PA form was purified to homogeneity by ion-exchange chromatography on CM-Sephadex C-50, immunoadsorption on purified anti-u-PA IgG-Sepharose and affinity chromatography on p-amino-benzamidine-Agarose. Typically, about 8-10 micrograms of purified scu-PA protein (antigen/protein ratio = 1) was isolated from 3-liter batches of heparin-containing serum-free conditioned media with a yield of about 41% of the total starting u-PA antigen. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of this purified u-PA protein showed a single Ag-stained band (nonreduced and reduced), with an estimated molecular weight of about 54,000, which exhibited very low fibrinolytic activity. Purified HUVEC-derived scu-PA did not incorporate 3H-labeled diisopropyl fluorophosphate. This protein did, however, exhibit very low amidolytic activity (approximately 5,000 IU/mg) on the u-PA-specific synthetic substrate pyroglu-Gly-Arg-p-nitroanilide, very low plasminogen-dependent fibrinolytic activity on 125I-labeled fibrin coated plates, and directly activated 125I-labeled plasminogen following Michaelis-Menten kinetics with high affinity, Km = 0.72 microM and low turnover number, kcat = 0.0005 s-1. Treatment with plasmin rapidly converted the HUVEC-derived scu-PA to the active two-chain Mr 54,000 u-PA form (approximately 90,000 IU/mg). Binding to fibrin clots, using antigen quantitation, indicated about 20, 10, and 90% binding for equimolar amounts of HUVEC-derived scu-PA, two-chain u-PA, and tissue plasminogen activator standards, respectively. These results indicate that subcultured HUVECs synthesize and secrete their u-PA protein as a single-chain molecule with low intrinsic amidolytic and fibrinolytic activity, high affinity for plasminogen and no specific affinity for fibrin. The role of scu-PA in endothelial cell-mediated vascular function has yet to be clearly defined.
We report on a patient with a large ischemic hemispherical stroke studied serially by 31P nuclear magnetic resonance spectroscopy. Persistent hyperglycemia was associated with prolonged acidosis in ischemic brain and failure of high-energy phosphate metabolism to recover. These in vivo human data support the concept that hyperglycemia adversely affects ischemic brain metabolism, pH, and clinical outcome.
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The posterior channel of duplicated urethrae usually follows a straight course to end in the perineum just inside the anal verge. This unique urethra dipped into the perineum and then turned cephalad to enter the rectum above the anus. Delineation of the course of the urethra simplified management by assisting the urologist to convert the rectal passage to a hypospadiac urethra.
alpha-Thrombin, DFP-thrombin, and ionophore A23187 induce the rapid release (less than 5 minutes) of a variety of proteins, including t-PA forms (Mr 110 and 70 k, after SDS-PAGE) from primary cultures, and both t-PA and u-PA (Mr 90 and 54 k) from subcultured human HUVECs. All PA activity forms are rapidly decreased in the releasates by some unknown mechanism. gamma-Thrombin does not induce the release of PAs from cultured HUVECs.
Pasteurella multocida causes hemorrhagic septicemia in many domestic and wild animals. The most common human infection with P multocida is a local cellulitis following animal-inflicted wounds, preponderantly cat bites and scractches. The typical clinical manifestations and complications have been well described previously. We present three cases of pulmonary pasteurellosis that were recently evaluated by the infectious diseases service at Barnes Hospital. In three additional cases, the technologists in the microbiology laboratory isolated P multocida from respiratory tract secretions.
Organization development can work: Valley Medical Center in San Jose, California, has successfully restructured multiple lines of authority in the process of installing modern management and fiscal control processes.
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A patient with constrictive pericarditis, secondary intestinal lymphangiectasia, and protein-losing enteropathy was demonstrated to have the characteristic immunologic deficiency associated with intestinal lymphangiectasia: hypogammaglobulinemia, lymphocytopenia, cutaneous anergy, impaired allograft rejection. and diminished in vitro lymphocyte proliferative responses. Following surgical correction of the cardiac abnormality, the intestinal lymphangiectasia and protein-losing gastroenteropathy resolved and was accompanied by a slow but progressive return of normal immune function. This documented reversal of the immunologic deficiency in intestinal lymphangiectasia supports the concept that the immune defect in this syndrome is due to the excessive loss of lymphocytes and immunoglobulins into the gastrointestinal tract.
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The enzyme, Pronase B, was used to extract the C carbohydrates of betahemolytic streptococci for serological grouping. Reference strains of streptococci, groups A through N, were accurately grouped by using this extraction method. Of the beta-hemolytic streptococci isolated from patients' cultures, 1,197 were classified as either group A or not group A by this method. There was 100% correlation with the reference Lancefield method. In contrast, false reactions occurred with the presumptive bacitracin disc method in 4.1% of the group A and 12.7% of the non-group A cultures. The Pronase method proved simple, accurate, and readily adaptable to the clinical laboratory routine.
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