274 research outputs found
Allergic and immunological aspects of therapy with cefotaxime and other cephalosporins
Immunogenicity and allergenicity studies in rodents show that cefotaxime and cefur-oxime are less immunogenic than benzylpenicillin or the semisynthetic penicillins. Cross-reactions of these antibiotics with benzylpenicilloyl-specific animal and human IgE antibodies appear minimal. Some cross-reactivity at the level of cell-mediated allergic reactions may, however, be expecte
Method for Rapid Interplanetary Trajectory Analysis using ΔV Maps with Flyby Options
This paper develops a convenient tool which is capable of calculating ballistic interplanetary trajectories with planetary flyby options to create exhaustive V contour plots for both direct trajectories without flybys and flyby trajectories in a single chart. The contours of V for a range of departure dates (x-axis) and times of flight (y-axis) serve as a “visual calendar” of launch windows, which are useful for the creation of a long-term transportation schedule for mission planning purposes. For planetary flybys, a simple powered flyby manoeuvre with a reasonably small velocity impulse at periapsis is allowed to expand the flyby mission windows. The procedure of creating a V contour plot for direct trajectories is a straightforward full- factorial computation with two input variables of departure and arrival dates solving Lambert's problem for each combination. For flyby trajectories, a “pseudo full-factorial” computation is conducted by decomposing the problem into two separate full- factorial computations. Mars missions including Venus flyby opportunities are used to illustrate the application of this model for the 2020-2040 time frame. The “competitiveness” of launch windows is defined and determined for each launch opportunity
Detailed site distribution of melanoma and sunlight exposure: aetiological patterns from a Swiss series
Background: The relation between detailed cutaneous distribution of melanoma and indicators of sun exposure patterns has scantily been explored in moderately sun-sensitive populations. Patients and methods: The precise site of 1658 primary malignant melanoma, registered from 1995 to 2002, in Switzerland were retrieved and clinically validated. Relative melanoma density (RMD) was computed by the ratio of observed to expected number of melanoma allowing for body site surface areas, and further adjusted for site-specific melanocyte density. Results: Sites of highest risks were the face, shoulder and upper arm for both sexes, the back for men, and leg for women. Major features of this series were: (i) an unexpectedly high RMD for the face in women (5.6 versus 3.7 in men), (ii) the absence of a male predominance for melanoma on the ears and (iii) for the upper limbs, a steady gradient of increasing melanoma density with increasing proximity to the trunk, regardless of sex. Age and sex patterns of RMD parallelled general indicators of sun exposure and behaviour, except for the hand (RMD = 0.2). Conclusion: RMD increased with (cumulative) site sun exposure, but a few notable exceptions support the impact of intermittent exposure in melanoma ris
A Generalized Multi-Commodity Network Flow Model for the Earth-Moon-Mars Logistics System
Simple logistics strategies such as "carry-along" and Earth-based "resupply" were sufficient for past human space programs. Next-generation space logistics paradigms are expected to be more complex, involving multiple exploration destinations and in-situ resource utilization (ISRU). Optional ISRU brings additional complexity to the interplanetary supply chain network design problem. This paper presents an interdependent network flow modeling method for determining optimal logistics strategies for space exploration and its application to the human exploration of Mars. It is found that a strategy utilizing lunar resources in the cislunar network may improve overall launch mass to low Earth orbit for recurring missions to Mars compared to NASA’s Mars Design Reference Architecture 5.0, even when including the mass of the ISRU infrastructures that need to be pre-deployed. Other findings suggest that chemical propulsion using LOX/LH[subscript 2], lunar ISRU water production, and the use of aerocapture significantly contribute to reducing launch mass from Earth. A sensitivity analysis of ISRU reveals that under the given assumptions, local lunar resources become attractive at productivity levels above 1.8 kg/year/kg in the context of future human exploration of Mars.Jet Propulsion Laboratory (U.S.). Strategic University Research Partnerships Progra
Nonsteroidal anti-inflammatory drug hypersensitivity syndrome. A multicenter study I. clinical findings and in vitro diagnosis
ackground: We present the results obtained from the largest series of in vitro diagnostic tests ever reported in patients with clinically validated
hypersensitivity to acetylsalicylic acid (ASA)/nonsteroidal anti-infl ammatory drugs (NSAID) compared with various categories of controls tolerating
ASA/NSAIDs. This multicenter study, which was performed within the framework of the European Network for Drug Allergy (ENDA) group, showed
that the basophil activation test (BAT), particularly when used with the 3 NSAIDs aspirin (ASA), diclofenac (DIC), and naproxen (NAP), allows
us to confi rm the diagnosis of NSAID hypersensitivity syndrome. The results of the cellular allergen stimulation test (CAST) frequently correlate
with those of the BAT, although not always. An unexpected fi nding was that basophil activation by NSAIDs is not an all-or-nothing phenomenon
restricted to clinically hypersensitive patients, but that it also occurs in a dose-related manner in some NSAID-tolerant control individuals. Therefore,
NSAID hypersensitivity appears as a shift in the normal pharmacological response to NSAIDs. These fi ndings allow us to formulate a new rational
hypothesis about the mechanism of NSAID hypersensitivity syndrome, a mechanism that most authors continue to describe as “unknown.”
Methods: We enrolled 152 patients with a history of hypersensitivity to NSAIDs and 136 control participants in 11 different centers between
spring 2003 and spring 2006. Flowcytometric BAT was performed.
Results: The most noteworthy results of our study were that 57% of 140 patients presented very clear-cut positive BAT results to multiple
NSAIDs, and 16% were entirely negative. In about 27% of cases, positive results were obtained with 1 or 2 concentrations of a single
NSAID. There is clearly a correlation between the results of BAT and CAST.
Conclusions: BAT seems particularly indicated in patients with a clinical history of NSAID intolerance, and in whom a provocation test is not
advisable for ethical, clinical, or other reasons
Women and Illegal Activities: Gender Differences and Women's Willingness to Comply Over Time
In recent years the topics of illegal activities such as corruption or tax evasion have attracted a great deal of attention. However, there is still a lack of substantial empirical evidence about the determinants of compliance. The aim of this paper is to investigate empirically whether women are more willing to be compliant than men and whether we observe (among women and in general) differences in attitudes among similar age groups in different time periods (cohort effect) or changing attitudes of the same cohorts over time (age effect) using data from eight Western European countries from the World Values Survey and the European Values Survey that span the period from 1981 to 1999. The results reveal higher willingness to comply among women and an age rather than a cohort effect. Working Paper 06-5
Metastatic melanoma in an esophagus demonstrating Barrett esophagus with high grade dysplasia
BACKGROUND: Metastatic melanoma involving the esophagus is rare; the occurrence of metastatic melanoma in a background of Barrett esophagus is rarer still. We report a case of an 80 year-old male who presented to our institution for workup of Barrett esophagus with high-grade dysplasia and who proved to have metastatic melanoma occurring in the background of Barrett esophagus, the first report of this kind, to our knowledge, in the English literature. CASE PRESENTATION: An 80 year-old Caucasian male was diagnosed at an outside institution with Barrett’s esophagus with high grade dysplasia and presented to our institution for therapy. The patient underwent endoscopic mucosal resection using a band ligation technique of an area of nodularity within the Barrett esophagus. Microscopic examination demonstrated extensive Barrett esophagus with high-grade dysplasia as well as a second tumor which was morphologically different from the surrounding high-grade dysplasia and which was positive for S-100, HMB 45 and Melan-A on immunohistochemistry, consistent with melanoma. Further workup of the patient demonstrated multiple radiologic lesions consistent with metastases. Molecular studies demonstrated that the melanoma was positive for the 1799T>A (V600E) mutation in the BRAF gene. The overall features of the tumor were most consistent with metastatic melanoma occurring in a background of Barrett esophagus with high-grade dysplasia. CONCLUSION: This case demonstrates a unique intersection between a premalignant condition (Barrett esophagus with high grade dysplasia) and a separate malignancy (melanoma). This report also shows the utility of molecular testing to support the hypothesis of primary versus metastatic disease in melanoma
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