5,425 research outputs found
Very high frequency digital rangine system
Digital ranging system measures slant range /from 500 feet to 200 nautical miles/ and provides digital range readout during range tracking between any two airborne vehicles
Safety and efficacy of tissue-type plasminogen activator produced by recombinant DNA technology
Because of its enhanced activation of plasminogen in association with fibrin compared with free plasminogen, tissue-type plasminogen activator (t-PA) evoked excitement as a potentially useful pharmacologic activator of the fibrinolytic system. Initial studies in experimental animals and patients demonstrated that it induced coronary thrombolysis rapidly and without concomitant, marked fibrinogenolysis in contrast to streptokinase. Large scale clinical trials soon followed. Their results indicate that intravenous administration of t-PA produced by recombinant DNA technology (rt-PA) elicits coronary thrombolysis in two-thirds or more of treated patients with angiographically documented thrombotic occlusions generally without perturbing hemostatic mechanisms or inducing marked fibrinogenolysis. Bleeding is usually confined to vascular access sites and episodes of major bleeding are rare. Overall 6 week survival for treated patients with documented acute myocardial infarction may be as high as 95%
Culture Wars and Opinion Polarization: The Case of Abortion
Recent observers have pointed to a growing polarization within the U.S. public over politicized moral issues-the so-called culture wars. DiMaggio, Evans, and Bryson studied trends over the past 25 years in American opinion on a number of critical social issues, finding little evidence of increased polarization; abortion is the primary exception. However, their conclusions are suspect because they treat ordinal or nominal scales as interval data. This article proposes new methods for studying polarization using ordinal data and uses these to model the National Election Study (NES) abortion item. Whereas the analysis of this item by DiMaggio et al. points to increasing polarization of abortion attitudes between 1972 and 1994, this article's analyses of these data offers little support for this conclusion and lends weight to their view that recent concerns over polarization are overstated
Ingenuous interpretation of elevated blood levels of macromolecular markers of myocardial injury: a recipe for confusion
AbstractSeveral assumptions about elevations of macromolecular markers of myocardial injury in blood require critical consideration. The dichotomy of modest, persistent elevations of troponins I and T as prognostic factors in patients with unstable angina and absent elevations of isoenzymes of creatine kinase is presently unexplained. Factors influencing the appearance of macromolecular markers of myocardial injury in blood are considered, including the need to estimate baseline values, to consider elevations as deviations from baseline rather than simply points within a distribution of baseline values in normal subjects, to recognize operative biochemical and physiologic determinants of marker release from injured myocytes and washout and to take into account the influence of apoptosis. Elucidation and consideration of mechanisms underlying the appearance of specific macromolecular markers in blood appear likely to improve diagnosis and explain the prognostic power of the troponins in patients with unstable angina. Detection of proteolytic breakdown products of troponins in blood is likely to explain the modest, persistent elevations seen in some patients with unstable angina and their prognostic implications
Vulvovaginal Trichosporonosis
Objective: Isolation of Trichosporon species from vaginal secretions is a rare event, and no data are available on its pathogenic role. A case series is presented to determine the pathogenic role of Trichosporon species in vulvovaginal infections. Methods: We performed a retrospective chart review of patients seen in the W.S.U. Vaginitis Clinic in order to identify patients from whom Trichosporon species were isolated. Results: Between 1986 and 2001, a total of 13 patients had a total of 18 positive vaginal cultures for Trichosporon species. All 18 vaginal isolates were T. inkin. In general, positive vaginal cultures were accompanied by low yeast colony counts. Four out of 18 positive T. inkin cultures were obtained from visits by asymptomatic patients. Of the remaining 14 positive T. inkin cultures from patients with symptoms, nine out of 14 cultures had other diagnoses (Candida albicans, six cases; bacterial vaginosis, two cases; Trichomonas, one case). Five positive T. inkin cultures were obtained from visits at which patients had symptoms and no associated diagnosis. In only one of the five episodes could we establish a clear pathogenic role for Trichosporon. In this case the patient was treated with boric acid and had resolution of symptoms and a negative culture at follow-up. In-vitro susceptibility tests revealed that T. inkin was resistant to flucytosine and susceptible to all topical and oral azoles. Conclusions: T. inkin is occasionally found in vulvovaginal cultures and is usually a non-pathogen. Transient colonization tended to occur in women, usually of African—American origin, with major perturbations in vaginal flora (bacterial vaginosis and trichomoniasis) and increased pH. Pathogenic consequences of Trichosporon colonization appear to be rare
Mary From Tipperary
https://digitalcommons.library.umaine.edu/mmb-vp/5194/thumbnail.jp
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Peroxisome proliferator-activated receptor (PPAR)alpha expression in T cells mediates gender differences in development of T cell-mediated autoimmunity.
Peroxisome proliferator-activated receptor (PPAR)alpha is a nuclear receptor that mediates gender differences in lipid metabolism. PPARalpha also functions to control inflammatory responses by repressing the activity of nuclear factor kappaB (NF-kappaB) and c-jun in immune cells. Because PPARalpha is situated at the crossroads of gender and immune regulation, we hypothesized that this gene may mediate sex differences in the development of T cell-mediated autoimmune disease. We show that PPARalpha is more abundant in male as compared with female CD4(+) cells and that its expression is sensitive to androgen levels. Genetic ablation of this gene selectively removed the brake on NF-kappaB and c-jun activity in male T lymphocytes, resulting in higher production of interferon gamma and tumor necrosis factor (but not interleukin 17), and lower production of T helper (Th)2 cytokines. Upon induction of experimental autoimmune encephalomyelitis, male but not female PPARalpha(-/-) mice developed more severe clinical signs that were restricted to the acute phase of disease. These results suggest that males are less prone to develop Th1-mediated autoimmunity because they have higher T cell expression of PPARalpha
Activation of prothrombin accompanying thrombolysis with recombinant tissue-type plasminogen activator
AbstractIncreases in thrombin activity in patients given fibrinolytic agents for acute myocardial infarction have been shown to be important in limiting the ultimate success of coronary thrombolysis. The present study was designed to determine whether increases in thrombin activity reflect, in part, activation of prothrombin accompanying thrombolysis. Plasma concentrations of prothrombin fragment 1.2, a polypeptide released when prothrombin is activated by factor Xa, were measured in 22 patients with acute myocardial infarction before and after treatment with 100 mg of recombinant tissue-type plasminogen activator (rt-PA). Concentrations of prothrombin fragment 1.2 increased from 0.83 ± 1.1 nM(mean ± SD) before rt-PA infusion to 1.5 ± 1.5 nM2 h after initiation of the infusion (p < 0.05). After a 5,000-U intravenous dose of heparin given at the end of the infusion of rt-PA, concentrations of prothrombin fragment 1.2 decreased from 1.8 ± 1.5 to 1.1 ± 0.9 nM(n = 20, p < 0.05), although values were still increased compared with concentrations before rt-PA.These results indicate that thrombin activity increases in patients given rt-PA at least in part because of activation of the coagulation system leading to activation of prothrombin. Thus, inhibition of the reactions involving coagulant proteins that lead to activation of prothrombin may be of value as conjunctive treatment to potentiate the efficacy of pharmacologic thrombolysis
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